Derek, I've used my '91 M5 as a daily driver for 2+ years (now with 103,000 miles on clock) and I love it. I always drive gently (i.e., under 3000 rpm ) until the oil temperature reaches ~140 degrees. Check oil level religiously--as these vehicles tend to have higher than average oil consumption esp. with enthusiastic driving. I had to replace my water pump at around 62,000 miles..(did radiator at same time since disintegrating water pump bearings' shrapnel/metal shavings somehow lodged themselves in the radiator capillaries when water pump failed)..total cost for dealer replacement of water pump and radiator around $700...but no serious work necessary since that, just maintenance items. I recommend keeping up maintenance esp. on oil/coolant/brake fluid/gearbox + diff. fluid. When you test drive these cars ; after warmup, try downshifts from 4th to 3rd, and 3rd to 2nd....make sure downshifts don't require heroic measures to accomplish or any grinding..(I drove two '91 M5's when I was looking which exhibited these symptoms and were perfect cars otherwise..but I resisted my lust for the cars and moved on to the third M5 candidate, which I now own)..make sure A/C works well--as I've heard it's big buck$$ if needing refurbishment. SPEND the extra $100 bucks or so to have a qualified BMW technician examine the car at a dealer..also have them check the condition of front thrust arm bushings..a $600 repair if needed, and all e34 M5's need it somewhere after 50,000 miles to maintain proper handling/suspension geometry and more importantly, & seriously, to keep the front wheels attached to the car.....Good Luck ,let us know how your search turned out , Damian..... I have a 90 535i 5 speed right now. Am going to look at an M5 this weekend. Am curious to hear thoughts from those that drive their cars daily as to any problems or issues. I am pretty familair with the general e34 issues, curious to hear more about M5 particulars.