I just bought a 93 es300 and was wondering if they are pre-wired for the changer? thanx

 

Some come with a changer. Some don't even come with one. Just be sure you bought an ES with one.

 

I think you can buy the second gen radio with the changer and just swap it with your old non-changer. You will have to take care of running a few wires here and there, however if you are good with that kinda stuff, then go for it!