http://www.amazon.com/SILGLYDE-LUBE-...5759678&sr=8-1
Lube the door seals with this.
I found out that when the seals "dry" up and touch the body frame of the car it will squeak.
Don't over-lube it since it can get onto clothing when people get into your car; your passengers will think you're having too much "fun" with the car.