Has it been stored over the winter months? If so, wouldn't really bother with the snow foam pal.. I'd tend to use that to help remove and break down the grime from the salty roads if it hasn't been stored.
Give it a good strong wash to remove the old wax layer, if you have a DA polisher, go over the car with lime prime or lime prime lite depending of the cut you require. If it was mine I'd go over it then with Megs #7 glaze, then a wax coat or two of your choice. Personally id still be using a good winter wax such as collinite 476 or 915, Valet pro Aramis is a great pre wax cleaner also, makes my 172 flamer gleam.
If you fancy trying a bit of the Aramis, pm me your address and I'll gladly send you a sample to try out.
Ian