Any ideas on making seat-belt buckles?

They have them here but are out of stock right now. http://www.scaledreams.com/DETAIL.HTM look under pe acc.

You might try a google search for the Detail Master set though.

Model Car Garage has a set for $6 here http://www.modelcargarage.com/mcg_display_item.cfm?m=2089

Hope those help you out some.

Where are they 5 bucks at? My local store has them for $13

Don't know for sure about the seat belt buckles except maybe try to form them out of aluminum foil. Something that small might be hard to get looking right. I would think that for the $5 or so that a pe set costs it would be worth it in this case. Plus you get a whole bunch of them. Heres a page that has some nice tips on getting the belts and other stuff looking good though:
http://www.briansmodelcars.com/tutorials/tutorial.asp?TutorialID=27&CurPage=1