Faults:

Battery needed to be replaced shortly after purchase; required "coding" to tell the computer that a new battery had been installed.

Water pump leaked; replaced myself.

Serpentine belt ruined from leaky water pump; replaced myself.

Serpentine belt tensioner ruined from leaky water pump; replaced myself.

Alternator required rebuild; removed it myself and sent to rebuilder.

Various computer faults mostly corrected using BMW INPA software (myself).

Coolant expansion tank ruptured; replaced myself.

Coolant return line (plastic tube) cracked; replaced with a steel brake line.

Oil seal behind alternator bracket leaked; replaced myself (what a miserable job).

Coolant temperature sending unit/thermostat has leaked from failed o-ring; replaced with Permatex gasket-in-a-tube.

General Comments:

As many BMW owners have said over the years, it's a joy to drive when it works. I really do enjoy this car a lot once I can forget about all the repairs I've had to do on a car with so few miles. Acceleration is top-shelf, braking is true and strong, handling is an absolute delight. It's very predictable and manageable, feedback is good, I never feel anything less than agile and light as I dance through traffic. There could be a little more sound coming from the V8, but that could be fixed by swapping out the exhaust.

The interior is very grown-up, the seats are very comfortable and supportive, it's handsome inside and a welcome place to spend time. I see why nobody liked iDrive at its inception, since it is a bit of a pain; changing the radio station is an exercise in fiddling, and I find myself more often than not just turning off the radio rather than try to shift and navigate the menus.

I've had to made several small adjustments to the computer system using BMW INPA software, which seems silly when all I want are small things like having the car unlock when I withdraw the key from the ignition. It's nice to have, but seems almost compulsory to own if you have this car—especially if you have to do any repairs.

I'll have to replace the driveline giubo, which is a big rubber disk that is supposed to smooth out shifting on a manual transmission, and I'll also need to replace the valve stem seals, which will put my repair skills to the test (not really looking forward to that job). I still don't know why it ticks loudly until it's warm, but I'm just choosing to ignore that for now (hopefully not a time bomb ticking).

Bottom line, this is not a reliable car by any stretch of the imagination, and when it does break it's expensive. I can buffer the costs by doing nearly all of my own work, but even still the parts are expensive. Simple belt tensioner costs $60, coolant expansion tank (big plastic bottle) was $120, new alternator would have been about $600 if I had not had it rebuilt for about $125. Don't buy this car (specifically the 545, which uses the somewhat problematic N62 engine) if you think you can just start it and go every day. This is the sort of car that will test you and perhaps break you unless you really like driving it. I'm sure that in the next couple of years I'll tire of all the repairs and get something a little more plebeian, but for now I enjoy storming down the freeway with the throttle on the mat, getting about 19 MPG on premium gas—but smiling the entire time.

Faults:

"General electronics" failure popped up frequently.

Always throwing up some sort of a fault code. In the end it was quite depressing to turn the key - you never knew which fault was going to pop up.

- Seat sensor passenger side, $1400 fix to get the airbag working at 120,000KM.

- Some sort of bushings in the rear, making a really annoying sound at 100,000KM.

- Light module went out, throwing fault codes that had to be replaced. Bushings and wishbones in front, suspension leaking at 122,000KM. All this cost me $4000 for parts and labour.

- "Transmission failure" fault code popping up sometimes, however I never noticed any fault in the transmission, it worked fine.

- Frequent need of wheel alignment.

- Kept blowing an ABS fuse.

- Front headlamp leaking, mist inside. Looks fugly and is an expensive fix.

General Comments:

Such a disappointment and expensive experience. This car has been a pain, I got rid of it after 1 year of ownership and sold it to a local. I talked to him some time ago and he's already spent $5000 on electrical gremlins and other fixes underneath the car. The car always started and drove, but there were so many absurd things that went wrong.

Economy was also very poor, power to economy rating, 1.2L/10km average mixed driving.

This car had been so much looked after, the service book was brimming with services from when the car was new to when I bought it and sold it, but still so many things went wrong in a short period. I guess some of the reasons things went wrong was that the 2004 model is the first one. I think that in the newer models, many electrical glitches have been sorted out.

All in all, this was not worth it at all, the car was not really THAT good to drive, but the comfort was good. Still, it doesn't justify the running costs at all. Got quickly bored of the car; I guess it's because of all the problems and expenses.