16v owner here. I use liqui moly 10w-40 hd for the engine, redline mtl for the tranny, redline shockproof light weight for the diff. I use BMW coolant. Kayang kaya DIY sa oto na ito, as long as you have proper tools. The immediate concerns for most 16v owners are the SLS system, shifter bushings, lap timer, ICV, cold start valve and the Air fuel mixture. I am keeping mine and now have spent a lot for the car. I changed the fuel system (70L tank, vdo fuel level sensor, governor, fuel pump, fuel relay, injectors, etc), delrin shifter bushings, SLS delete, bilstein sport shocks, h&r race springs, sls pump cover, braided brake lines, 500e w124 f/r brake upgrade.. I am now waiting for my sway bars to arrive too. I have a lot of parts still lying around that I haven't installed yet due to a busy schedule. I suggest you visit
www.190rev.net for tips and inquiries for maintaining your 16v. Now, my car does not ride like a benz, medyo nasa harsh side na siya but on sierra madre fun runs, ahhhhhh... rewarding lahat ng ginawa ko.. never tried it on the track though. Addicting ang hagok niya.. hehe..