How do good car amps sound?

Do car amps sound good - liquid and transparent? They are certainly affordable and small enough to fit on a computer desk, so I am thinking of getting one and building a nice computer system for cheap.

Which sounds better - class A/B or class D?

If anyone knows of a good sounding car amp, please enlighten me - I will be most greatful.
Most automotive amps don't sound good, the head units usually sound better but with less power. Not sure how you plan on powering this unit, with a 12volt battery or 12volt power supply ? A/B is usually preferred.
if you're looking for a compact power amp for a desktop check out a gainclone or a T-amp. They sound wonderful, though not necessarily high power (gainclone amps are ~30 - 45 watts; T-amps ~10 watts)
Thanks Bd - I checked out the Dayton T-amp and they sounded quite good. I have to see if I can hear gainclone ones - which ones better?

Also thank you Tm for your informative voice of experience... I will be using a power supply.
There are some outstanding car audio products which do all the same things that audiophile home amps do, you just need to know where to look.

Check out brands like Audison and Sinfoni, both which are heavily biased into Class-A operation.
Naim's system in the Bentley has been very highly rated :)

I use JL Audio XD amps driving the Dynaudio Esotec 242GT (basically the drivers of their Focus 140s) with an Alpine INA W900 head unit. iPod carrying AIFF
Audison is very good.