My 06' Z4MC is on 65k miles now, doesn't miss a beat. I can understand a little people's worries with 'high' mileage cars as I too was one of them, only looking at cars under 40k miles before I bought my M.
But the car I have now has been well looked after, I garage it everyday and cherish it with care and love

. It has good spec and is problem free so I'm more than happy with it. It turns heads and gets the same attention and respect as any other MC with half the mileage would.
65k miles might sound 'high' to some but when you think about it, that's approximately 10k miles a year, which is about average or maybe just under. I do about 6-7k miles a year but as long as the SH is all good and the car stacks up like mine does then that should be fine.
I could've spent an extra couple of £k and got something with say <40k miles on so it's all relative, plus it would've meant an imminent Insp2 aswell. From what I've seen and heard these M's will last well over the 150k miles, so there's a lot of motoring left.
People really shouldn't get hung up on mileage as much as they do, these cars were made to be driven not locked away. And if it has 100k miles but good SH etc, then it'll be cheaper so more affordable to others who can't afford one with say 20k miles on, it's all relative!