Wash the car with regular soap one more time and dry thoroughly. As a final measure, do a final wipe-down with IPA - a 50/50 mix of isopropyl alcohol and water. WARNING: Don't use any waterless wash products before applying your new ceramic coating!

Does IPA damage ceramic coating?

Just be mindful that exceeding more than 14-ounces of 50% IPA in a 32-ounce batch will result in a solution that is entirely too strong for most ceramic coating surface prep situations.

Is IPA safe on car paint?

Isopropyl alcohol should be diluted between 10 and 15% before being applied to painted surfaces. Isopropyl alcohol is NOT recommended for freshly painted finishes. You should never use isopropyl alcohol at full strength or it could permanently cause damage to your vehicle's paint.