Great grilling, an American Tradition, starts from the moment of purchase. Load purchased meats in the front air conditioned portion of your car and not in the back where it can get really hot. Take meat straight home. If your drive home is more than 30 minutes, take a thermal cooler to load your perishable items. Refrigerate items immediately.
Marinades have a multitude of uses.
They tenderize the tough, moisten the dry and enliven the bland. Marinade recipes require that the meats marinade for anywhere from 30 minutes to 2 - 3 hours, and should always be done in the refrigerator and not on the counter top. BBQ sauces should be placed in small, separate bowls for coating. If you spread from the container directly onto the raw meat, you have contaminated the whole batch. The oils in the marinades insure that the products will not stick.