I think your problem is that, with your budget, you have resigned yourself to not being able to have the entire wish-list -- you'll have to look at earlier M-B or BMW models which may not have all the latest in airbags. Perhaps the solution on your budgeted amount is to go to a lease and get a Starmarked C36 AMG or C43 AMG, extend the Starmark warranty and lease it for the warranty period -- both have plenty of power at the low end without a manual, as well as M-B solidity.
If you need the manual for control and low-end power by holding it in a lower gear, then perhaps you should look at leasing an off-lease manual 3-series -- but only M-B will provide a factory warranty as far back as '93. If you prefer an automatic, then the M-Bs are in the mix.
For something completely different, what about a Honda S2000 -- tremendous handling, very good performance in crashes (a number of the hot-rodders with this car have managed to overcook it and walked away:
http://www.s2ki.com/forums/forumdisplay.php?forumid=1), but probably useless in snow -- Blizzaks or Alpins may enable you to get around -- or, for an all-weather interceptor, the AWD Subaru WRX -- not a BMW or Benzer, but within the budget limitations and fun to drive.