@gogadrum. hi I have got this in Sept 2005 and so far it is still there and it lasts for about three years. Cleaning is still very easy and it shines like a new car.
Washing would not remove the sealant and it would also do no harm to car paint. It is in fact meant to protect and extend the life of paint.
In nutshell there are no problems attached with RoyalShield.