Well, depending just what you want to do, really inexpensive "Hawthorne" type cars are always floating around on ebay, and they make a great base for the much more true to life passenger car kits available from Deerfield River Laser. Check this out if you're not familiar and give it some thought. Not connected in any way, just a satisfied customer-I've built about 15 of their kits and really like them. Check here: https://www.deerfieldriverlaser.com/