1Z Perls Shampoo. But there are several other good car washes out there. Just do a search. Washing is important, but it's not nearly as important as the steps that follow. I mean, you can use a decent wash, so long as you dry it well and then follow up with the Klasse, etc...

Realize, this was a day and a half of working on the car. You won't have to do this every week or anything, but it does take awhile to get it right. After I washed the car, I got out my shop vac and air compressor to dry the car off. Forcing 125 psi air into the creases and joints to get the water out and using the blow side of the vac to help dry the water also. Remember, when you wash, don't spray. Just use the water coming out of the hose as it is. The lower pressure helps to get the water to bead and slide off the car.