I own a BMW 7-series, longwheelbase. I spend about $500 a year on repairs, if at all. It drinks gas and oil, uses tires on a yearly basis, and it has been doing 25-30k a year for me. Parts are only expensive if you pay retail. If you have the time, a radiator replacement that is $800 all day at a shop, will take a first timer three hours and $300.
The seats are heated and adjustable in ways the other import brands are just not accomodating for someone that is 6’3". You know why you want luxury, and that does not mean it is not going to be reliable.
Luxury brands I have owned Audi, Acura, and Lexus (when I worked for Lexus!), have left me stranded. BMW has never left me stranded.