Nothing, very reliable.
I'll go into pros and cons of my tC:
Cons:
* Completely insufficient leg room - even worse than the mid 90's Nissan truck I used to have
* Windows rattle if you have them down just slightly (did that even when it was new)... you need to leave them all the way up or all the way down
* A/C is fairly weak even on full blast (took about 15 minutes to cool down the car on the way to the beach today when it was 87 here)
* Handles very poorly for a coupe - lots of body roll and lack of steering feel... doesn't handle anywhere near as well as the 240SX I used to have
* Surprisingly bad turning radius for a small car - U turns are a chore... nowhere near as tight as the 240SX
* FRONT WHEEL DRIVE drives me crazy! The tires always spin if you accidentally press the gas too hard
* Clock and outside temperature gage are shared, so you can only display one at a time
* The seats are made of a nice material, but they are not supportive enough for me... my back hurts if I drive it for more than 1 hr at a time
* The entire roof is made of glass, so the car gets scorching hot on hot days
* BLIND SPOTS are dangerous. I got a ticket recently for "unsafe lane change" when I accidentally cut off a cop who was in my blind spot even though I tried to use the mirrors and turn around to look. That's at least the 6th time in the past yr I've gotten into a near-accident because of blind spots. The pillars on the hatch are WAY too thick for safe visibility.
* Car supposedly has 160hp, but it doesn't feel as fast as the 240SX I used to have - could be because of front wheel drive (tC) vs. rear well drive (240SX)
Pros:
* Absolutely bullet-proof reliability
* Gets 34mpg on the highway if you set the cruise
* Hatchback has a lot of room especially with rear seats folded down
* Rear seats have a lot of legroom for a coupe (probably because you can't put the front seats back very far!)
* Nice rims, headlights, and taillights
* Soft clutch and smooth shifting make it easy for someone who hasn't driven a stick before (this is my 5th stick shift, but I'm just saying)
* Nice stock radio/stereo system
* Steering wheel radio controls are awesome
* Auto up/down for both windows comes in handy.
I've had my tC for about a year. I expected it to be a great car that I'd keep for a long time, and from a reliability standpoint I still think that would be true. However, its performance just isn't good enough for me to keep it, so I'm selling it now and getting a Subaru Impreza WRX STI (drive one, and it'll be your dream car, too). My pros and cons detail exactly what you'll experience with this car - if reliability is your thing, get one. If performance is your thing and driving excitement is, look elsewhere.
Have you had any problems with the clutch??
Well I guess I never had any mechanical problems that required fixing, but I did notice that it would miss 3rd gear on a fairly regular basis. Also, the clutch wasn't precise, so it was a jerky ride, especially compared to the STI I replaced it with (drives as smooth as an automatic).