I'm using a foam gun on my X5 and would like to know which car wash soap makes the most foam/suds.

I've tried Meguiars Deep Crystal (not very good, but is good enough to clean brake dust off my wheels) and Turtle Wax Platinum Ice (better than the Meguiars, but still not great.

I'm looking for something that looks like I sprayed the car with shaving cream.

Thanks in advance! :