I think I'm going to be looking for a used E92 M3 soon, and am wondering which on-line sites I should consider. I typically look at BMWCCA, M3 Forum, and Ebay. Are there any others recommendations?
Autotempest.com searches ebay, craigslist, vehix, autotrader, cars.com, and carsdirect.com. As craigslist doesn't offer a comprehensive nationwide search function, Autotempest is very useful for that. Searching ebay & autotrader yourself may allow for finding more comprehensive results than through autotempest. You might want to search car magazine classifieds as well, such as Car & Driver, Autoweek, Road & Track, & Hemmings. And through any BMW or M3-specific site/forum for-sale sections. A dealer may be able to check CPO inventory across the country as well.
can also try roadfly.org! i also like to check out forum for sale sections, in your case e90post.com and m3forum.net