My 2007 Tucson, which recently had it's 60K service at the dealership, stopped blowing cold air in the middle of a 10 hour roadtrip on a 100 degree day - not happy....
I paid a AAA Car Care Center (Hyundai dealership was backed up) $1200 to replace the compressor, receiver dryer and evaporator expansion valve.
The A/C is now blowing cool air, but not cold air like it had originally.
When I took it back I was told that it was impossible to make it blow any colder - something about newer air conditioning being "funny that way."