Be gentle with the Smart Key ignition tumbler, if it breaks, you are looking at least 1000 to repair it. I woudnt do kickdown if you are near time for an oil change but is safe doing after an oil change as the lubricant will protect your engine at the high rpms. Ive used kick down on all my MBs and other cars Ive owned with no subsequent engine or transmission problems. Be gentle to the tires as they are very expensive to replace (just paid 600 for MXV4+). Dont change the stock rims as the bushings will be destroyed. Do oil changes every 5000 miles with Mobil 1 synthetic. Read the D.I.Y. section and do oil changes yourself with a topsider so that you can save some money and correctly fill the crankcase w/o overfilling.