If you replace the factory head unit with an aftermarket stereo, do you lose the steering wheel cotrol functions?

yes but their is a modual u can install and get them back im condiering doing it myself.

yes you need the PAC SWI-X. works perfectly with aftermarket headunits. only one factor. the headunit needs to have a remote

has anyone here installed one?

now that i see that you have a 2000 I think that there are some problems that are persented. I think that the 2000 have a serial cable or something weird. there is a aftermarket interface that will work but I am not sure that the PAC will work, they may have a model that works

I have not installed in one in MY car (soon to change) but yes I have experience with one, what questions do you have

how hard are they to install? are they (plug and play) style of device? i really dont want to cut any wires(fear of cutting wrong wire). is their pics of install?

I would say that it is like an 5 on a 1-10 scale. there are some wires the need to be spliced in but it is a easy install. all the wires are easy access and they are all in the radio harness.

I've done it, and they suck. They're unreliable, and not worth the time or money. I gave mine away after 60 days. The guy I gave it to threw it away after a couple weeks.

Save your money.

I usually don't do this but I have to disagree with Bill. I've had mine installed in the Riviera for over a year and it always works flawlessly unless there is direct sunlight (very bright mind you) on the faceplate of the radio. Other than that it'* great.