I am in the market for a fine example of the 6 mark, I have located a M6 with 133000 miles on it that fits the bill however having only experienced a 633 with a 50000 mile ( which I lost to a curb) engine gives me concern. Am I getting into a car that is going to eat me alive, it will be a garage queen not a daily driver. Just how much attention do the Ms take over the 633 & 635. Should I look for a 635 instead? Thanks Ed Resh