I don't think the dealer does a fantastic job on the pre-delivery cleaning. Every time I buy a new car I will spend a whole day re-cleaning. I apply a good wax and use a stain protector on the fabric, use silicone based protectant for all the rubber gaskets and what not, treat the leather with a moisturizer, etc...
Anyway, as MattMan mentioned, your choice of applicator and buffing material is very important. Use something soft and CLEAN! For example, if you're washing your car and you drop the sponge, don't just pick it up and keep washing. Rinse it and wash it until you're absolutely sure there is no contaminant remaining. Also, it is important to wax your car immediatley after washing it. Don't wait a few hours or do it the next day. I once saw a guy waxing his car after a thick layer of pollen had settled on it. He was just buffing that yellow dust right into his paint. I almost cried but it was a honda so I didn't.