Meguiar's Clay Bar Kit is a good off the shelf kit to buy. If you have a full day to spend soon, wash the car with dish washing soap first. It removes all existing wax. Hand dry with soft cloths. Clay bar entire painted surface. Apply a hand wax. Meguiar's Gold Class is a nice kit, as well. I use both these, myself. My SS is white so the finish and feel are amazing IMO. After complete, you could either use a California Duster for daily/weekly maintenance or use the Meguiar's Quick Detail Spray with a soft cloth. Trust me, your 300s will give it that extra special look.
