So to prevent more damage and creating additional cost
for your self later down the line so a super-safe wash is the order of the day.

Wheels, tyres and arches are generally cleaned first simply because they tend to be the dirtiest therefore it makes sense to get them out of the way. So assuming all four corners have been adequately tended to, the first real stage of the safe contact clean is to snow foam the car dry which means applying it prior to any pre-rinsing.
I’m aware plenty of people prefer to pre-rinse first then foam and contact wash in one go but I’d recommend doing both on a swirl-free car if possible. A dedicated snow foam applied to a dry car first will help soften up, break down and lift off loose surface dirt more effectively than a straight up pressure rinse which will allow you to essentially remove more dirt prior to making contact.

I’m sure I’ve said it before but for me, in terms of swirl-prevention, this is probably the most important part of the wash process. The more thorough job you do here the less chance swirls will be inflicted later down the line so it’s worth going the extra mile to ensure the car’s as clean and contaminant free as possible prior to touching it, even if that does mean triggering the short-sighted ‘Green Brigade’ for quote unquote wasting water.
Now this is were things can potentially get a little time consuming but ultimately I think it’s worth it. So instead of just going straight to contact washing )which of course you can), I suggest re-foaming the car but this time with the shampoo you’ll be using to wash it which will provide some extra lubricity. Yes, it’ll create a bit more mess and mean emptying out and re-filling your foam bottle if you don’t have a second dedicated one but if you want optimum protection for corrected paintwork when washing then it’s definitely worth doing.
A plush mitt is a must when washing corrected paintwork and so long as it’s clean and of a decent enough quality, it can be either a synthetic, micro fibre or lambswool item. Another crucial component to the contact wash is the two bucket technique which for those of you that don’t know is a system that utilises two separate buckets; one for rinsing your mitt out after washing a dirty panel and one for reloading it with suds. They should also both contain a grit guard of some sort which simultaneously helps dislodge any dirt particles while holding them at the bottom of the bucket out of harms way.

Assuming you’re employing a two bucket system and using a nice clean, plush wash mitt then, you generally want to clean the car from top to bottom, gently gliding the mitt over the surface in a manner that roughly follows the contours of the car. There’s no need to apply any real pressure or scrub away at the surface, instead the aim is to simply keep the mitt in contact with the car so the dirt can be gently dislodged and gathered up by its fibres.
The two bucket technique isn’t a complete failsafe but it does help considerably minimise the likelihood of swirls and scratches being inflicted. As I’ve already said, I personally consider the pre-clean to be slightly more important in terms of swirl-prevention as that’s were the bulk of the abrasive dirt is safely removed, however when actually making contact with the car a two bucket, soft mitt wash is still definitely worth doing.
Being in closer proximity to the ground, the lower parts of a car tend to accumulate the most dirt so instead of contaminating your relatively clean upper-body mitt with dirt from these parts and hoping it all washes out before using it again next time, it makes sense to use a second mitt reserved for these grubbier areas to keep things in check.
After being gently contact washed you then obviously want to thoroughly rinse the car down before drying it and something that will make that drying considerably easier and less invasive is a de-ionizing water filter which theoretically allows you to let the car air dry naturally without having to make any contact with it.
If you tried this without a suitable filter, unless you happened to be exceptionally lucky, you’d likely end up with unsightly water spots everywhere which in some cases can be more difficult to remove than swirls and scratches, so if you can, it makes sense to go with filtered water for the final rinse.
Once rinsed off then wether with filtered water or not, another thing you can throw into the anti-marring mix to prevent having to draw a towel across the surface is to blow dry the car. Being mobile I only carry a mini blower to save on space which I generally reserve for use on wheels and a few other nooks and crannies and while you can’t realistically expect to dry an entire car with something this size, you should still hopefully be able to get a good idea of how drying a car in this manner would work.
Polished and protected paintwork should be smooth and hydrophobic enough so that any standing water rolls right off with minimal fuss. You could use one of these instead of a water filter or for complete contactless drying, combine it with a filtered final rinse so you don’t have to wait for a wet car to air dry which can be inconvenient if you have other parts of the detailing process to be getting on with.
Now, fancy water filters and blow dryers are all well and good but for those of us that still like to get hands-on with our cars, the good news is that they can still be safely towel dried so long as some care’s taken. A nice thick, plush microfibre drying towel will help reduce the likelihood of any marring being inflicted as it’s that, not swirls which are more likely to foul the finish at this stage so don’t cheap out, go for a quality item and machine wash it after every use to keep its fibres soft and clean.
For the main flat panels like the roof and bonnet you should simply lay the towel on the surface before gently patting or dabbing it to safely soak up the rinse water instead of wiping it back and fourth because scratches and imperfections can only really be inflicted when movement’s being made so less movement technically means less damage.

There will of course be parts of the car where drawing the towel across the surface is necessary but so long as it’s done in the right manner, shouldn’t be an issue. The secret for me is to spritz a light detail spray or drying aid over the surface first which like when adding an extra layer of shampoo earlier, adds some additional lubricity allowing the towel to glide more freely over the surface.
As with the washing you only really want one, perhaps two passes of each area with the towel and no scrubbing back and fourth, just nice light sweeping motions. Think of it more as pampering the surface instead of cleaning it and of course keeping in mind how much blood, sweat, tears or cash you put into correcting the paintwork should also help keep you on the non-scrubby straight and narrow!
And that’s pretty much all there is too it. It’s really just about finding that balance between simplicity but still taking enough precautions to ensure swirl-free paintwork that’s had a lot of time put into it remains that way.
So to quickly recap the process and leave it fresh in your mind then, I suggest you snow foam a swirl-free, presumably dirty car dry with a dedicated product, allow it to dwell for a few minutes to soften up and encapsulate the muck, then spend some time thoroughly rinsing it off to remove as much of it as possible.
You should then ideally re-foam the car with the same shampoo you’ll be using to wash it to add some extra lubricity and only then should you contact clean the car with a soft mitt or two from top to bottom, making sure to employ the two bucket technique.
Once washed, ideally give the car a final rinse down with filtered water and or blow dry it with a suitable machine to prevent having to draw a towel across it. If you do have to dry the car with a towel, just be sure to use a decent quality one and dab it over the surface where possible or lubricate with a light detail spray or drying aid when wiping and if you do all that correctly then you should still be left with a swirl-free motor.
Now unfortunately there’s no guarantees and the steps outlined here are simply designed to minimise the chance of damage being inflicted, as the truth is anytime that contact’s made with with a car during the wash process then there’s a distinct likelihood of unwanted marks and blemishes being left but that doesn’t mean you shouldn’t actively take measures to reduce it.
It may seem a bit much to some, while other’s might even want to add to the process but in my experience following this particular procedure should greatly reduce the likelihood of imperfections being inflicted without calling for excessive amounts of time, products or equipment.