Check out the N resin cast vehicles offered by Lineside Models (formerly Road Apples) listed here http://hometown.aol.com/yvelmd/lsm.html (If the webpage does not load right away, hit the "Refresh" button on your browser). Courtesy post -- no affiliation eNjoy
Yep, they've got some great stuff, although I'm still waiting to see the modern ambulance they've told me they'll be coming out with. And just to join the club, I too have no affiliation with anything, just float freely in my own model railroading reality!