My wife and I feel in love with our 05' BMW 645i conv. when we first picked it up. We purchased it Jan. 2011 used with only 33,000 miles on it. It had some years on it but we figured it would get several years of only normal maintenance type services and not need to worry about major mechanical or electric problem because of it's low mileage and series. After all this is one of BMW's flagship cars. While the car gets looks of admiration at stop lights the feeling of this wears out quickly when you count how many dollars and time it has spent in a BMW repair shop. The BMW 645i is like buying a boat - the 2 happiest days of ownership are the day you buy it and the day you get rid of it.
Owned a 308, a 365, two Aston Martins, a slab sided Cobra, more MBZs than I can forget and I have to say this is the finest all around automobile I have ever owned. The car is dependable, forgiving and a joy to drive hard and fast. Spent 14k at 90,000 to replace items that had not yet failed but what does it matter since my old chum has never let me down. Am now at 203,000 miles and all is still well.
Drove 3-series all my life until I got this beast. 6 speed is out of this world. Acceleration, handling and cornering couldn't be finer. I swapped out the run flats immediately even though there was only 19,000 on car. What a difference without that extra weight. Less expensive too. First gear buries the tach a little too fast but you get use to the quick shift to second. I took it to the limit 160+ once and it was still quiet in the rag top. The iDrive is simple once you read the manual. Quality and variations of the LOGIC7 is theater- like. I'm 6'7" and the cockpit is very accommodating. I just love my BEAST for power and style.
We loved everything about our 2005 645I convertible. Talk about a car that catchs everyone's eye and is a blast to drive! But....we had so many problems with ours we regretfully ended up giving it back under the lemon law. It was in the BMW service dept 32 days between July 6 and Oct 1, 2006 - not counting weekends! We were told it had 19 computers by 15 manufacturers and the glitchs weren't worked out yet. We expected more from an $80,000 car but agree we'd buy another one if we were promised it wouldn't have so many problems!
Reliability is an issue - right now I need to take the car to the shop to get the engine gaskets replaced, the intermittent PDC failure analyzed, the trunk lock sensor fixed so that I can open it with the remote, the brake fluid flushed, the interior filter replaced, brake pads replaced, etc.