[QUOTE=SleepingStang;924681]For the stripe it is my opinion that you would not need any flex agent. A lot of painters don't even use flex anymore with the new paint compounds.[QUOTE]
We have 5 automotive painters in my area. Every one of them uses the flex agent on urethane parts except for one. Needless to say, his paint jobs on urethane bumpers did not last and cracked all over within a year at best.
Can you guess which painter is out of business now?
Having been involved in numerous paint jobs myself, I would advise using the flex agent or a paint that is formulated for use on urethane.