Dealer
Thats the first place I would try. I've found cars almost completely stripped and beat to hell and the weatherstripping was in great condition.You can always check local wrecking yards also. I was just pullin a lot of items off of one at a wrecking yard near me and noticed that the weatherstripping for the doors was flawless. Imma go back and get it once my current goals regarding my supra are attained.