regarding your example, i think there are too many options or opinions to pick the "best" head unit -- people are going to rate various things (iPod compatibility, satellite-readiness, faceplate color, the fact that is a certain make) very differently. i couldn't care less about the iPod compatibility, but someone else may say that the "best" radio must have it. I absolutely will not buy anything Sony, but someone else may think they are the "best".
i'm not trying to deter you, but picking out the "best" mods is tough because people like very different things -- listing all the mods would help more than just listing particular ones --
keep us updated.
Needless to say, you are correct. I was thinking the "best" would simply be the most often recommended in general. So if the Pioneer such and such is most often recommended, then it would be the "best". We could make it so one could also search by feature, say ipod compatibility and such. Of course, all mods in all categories would be listed.
It occurs to me a wiki for how to's would be useful as well. Thoughts?