[QUOTE=rh71;836319]my SA says these batteries are supposed to last 7 years. Maybe he's talking about normal driving with a lot of highway...

They used to......not so sure about more recent batteries in BMW's with i-drive and automated this and taht.

My 1998 M3 (almost 14yrs old) is on it's second OEM BMW battery. However, it gets driven about 1,000-1,500 miles a year and sits with a trickle charger the rest of the time.