Soaking? Seriously? Buy the Dr. Beasley kit, and you'll have enough product to last for years... It comes with a smaller spray bottle of the Paint Cleanser, which you spray on, wait maybe 15 seconds, and wipe the bugs/tar right off. Or, you can just buy the larger size bottle of the cleanser:

https://www.drbeasleys.com/matte-paint-cleanser.html