Since I found out I am moving to that area, I did what any sane person with very little disposable income would do: troll CL
And WOW did I find weird/rare/GRMey stuff. For example:
https://boise.craigslist.org/cto/4477714554.html
https://boise.craigslist.org/cto/4533378406.html
https://boise.craigslist.org/cto/4576060454.html
https://boise.craigslist.org/cto/4555104125.html
https://boise.craigslist.org/cto/4564533004.html
https://boise.craigslist.org/cto/4565277236.html
https://boise.craigslist.org/cto/4555929523.html
https://boise.craigslist.org/cto/4537116231.html
https://boise.craigslist.org/cto/4574512378.html
https://boise.craigslist.org/cto/4574435598.html
https://boise.craigslist.org/cto/4569099338.html
And that is just a small sample of weird/cool E36 M3 I have found.