At 44,000 miles the heated seats stopped working. Took it to the dealer. Said they work fine, just they're very subtle.
At 44,000 miles the CD volume would fluctuate by itself. Adjusting that setting didn't seem to make a difference. 2 or 3 months later it magically works.
At 46,000 miles a transmission line blew and I was charged almost $700 to fix.
At 46,000 miles the stock wheel rusted in a place that made the tire unable to bead. So I bought some wheels off of a BMW M5.
At 50,000 miles the car shut off unexpectedly on the highway and registered 10 different faults on the ODBII codes. Upon restart, it was fine. I cleared the codes and never had a problem since.
At 51,000 miles the car needed a new mass airflow sensor. Cost around $600.
At 55,000 miles the rubber hose that carries the washer fluid to the wiper broke. A little bit of super glue fixed that.
Recently the car will not lock when I press the lock button on the ring. It makes a loud beep like the door is still open. It also dings when the door is open like I still have the keys in it. Does it every now and then. Still have not fixed this.
Now at 56,000 miles my ABS light is on, and I'm getting a problem saying TRAC NOT AVAILABLE, ASC NOT AVAILABLE. This is bad especially in Wisconsin when the roads are icy. Would help if I had winter tires instead of all season.
For such a beautiful car, it is very unreliable. It's fun to drive, the performance is decent (would be better if I had the XJR).
It is amazingly comfortable (minus the lack of rear legroom).
I should have got that CLK430 I was looking at instead.
UPDATE: 60,000 miles, the transmission blew. I still owe $11,000 on the car. I'm just letting it sit in the driveway while I drive my Cadillac.
My friend, I'm very sorry but you are in the same boat I was in. I also got the ASC warnings, then bam... no more tranny. It's a shame something so comfortable can be such garbage.