I unfortunately cannot attest to the reliability of BMWs. I have been driving BMWs for the last 6 years now, but these were all company cars, which I swapped every 2 years. So never done more than 130.000 km on any of these cars. What I can attest to is that in these 6 years, I never had any, seriously any, problem with these cars. The only thing I noticed was the maintenance cost, which I luckily didn't have to pay. For example, the brakes on these cars are awesome, but you must replace them often. Worst case I had was with a Mini, in the two years I drove it (~130.000 km total) I had to replace the front brakes 3x and rear 2x. When I asked the mechanic if this was normal, he said yes.