The biggest mistake you can make when drying a vehicle is applying too much pressure…
Griot’s Garage Car Care Tip: How to prevent swirl marks
A common mistake when using a drying towel is rubbing hard on the paint to remove remaining contaminants. This drives the dirt into your paint, causing micro scratches (and maybe some not-so-micro scratches).
If dirty spots are stubborn enough to resist washing, follow up with some speed detailer or a shot of waterless spray-on car wash. These products soften and lift contaminants, allowing you to safely whisk light dirt away from your paint. We highly recommend using high quality microfiber towels. Another scenario that may require enhanced lubricity is when too much time passes between the final rinse and drying. In this case, a quick re-rinse is in order.
In some cases, a full rewash of the area may necessary. If you are having a hard time working the grunge out, consider a microfiber wash mitt with a textured surface that roots out the dirt while still safeguarding the finish. If bug jerky, bird droppings, or tree sap are the culprits, you may also need to use a purpose-made bug and smudge remover to punch up your cleaning power.
Bottom line: The drying process is for drying, not eradicating that last remnant of dirt or grime. Stay swirl-free!