I stumbled upon a really cheap diecast and plastic toy car on eBay for $5.69 with free shipping. I had to find out what it was all about at that cheap price and ordered one. 1/43 scale is a nice size for all but the largest or smallest putz houses. The same seller has two other cheap cars that would work well also. I am nothing more than a satisfied customer sharing info with other putz artisans. These are cheap enough that no one would be afraid to add some spray on snow, a Christmas tree on the roof, etc. The auctions show shipping from China but mine arrived quickly from CA.
Here are individual links:https://www.ebay.com/itm/1-43-Scale-Oxford-Austin-Seven-RN-Saloon-Westminster-Diecast-Vehicles-Green-Car/162645414780?hash=item25de6c137c:g:UvAAAOSwhMpZn-OEhttps://www.ebay.com/itm/1-43-Skoda-Hispano-Suiza-Alloy-Diecast-Plastic-Classic-Vehicels-Car-Yellow-Gift/152677198580?hash=item238c452af4:g:sTkAAOSwDehZn9~5https://www.ebay.com/itm/1923-Ford-Model-T-Black-1-43th-Alloy-Diecast-Car-Convertible-Vehicles-Kids-Toy/162645423364?hash=item25de6c3504:g:UpkAAOSwHixZn-Xm