No car is going to blow cold air from the get go when it's been sitting outside for hours with the windows up on a sunny 90 degree day. The dash board and associated vents will be extremely hot. The R34 and compressor need a little time before they start working plus you need to vent out all the heat in the dash and interior.

Suggestions:

1) Crack the windows
2) Use a sunshade
3) Tint the windows
4) Open the windows before getting to the car
5) Drive with the windows open for a few minutes to vent out the car

 

Some cars do blow cold air immediately from the get go. My wife has an '06 ES330 and the A/C blows cold air from the moment you turn it on. I confirmed it this morning when I got back from vacation after the car had been sitting in the sun for a week and it was close to 90 degrees outside when I got in the car. This was why I posted the question in the first place since my G35x takes a while for the cold air to start out.

I have already been doing everything you suggested but I don't think that getting the hot air out of the car by opening windows, etc. has anything to do with what blows out of the vents. I guess I'm going to take it to the dealer and check to see if anything is wrong.

 

That is absolutely right, the temperature of the air coming out of the vent should be cold, of course, it takes a while to cool the interior, but go by what comes out of the vent, do you have a thermometer, like a darkroom thermometer you could stick in the vent?