We've searched the internet and found the largest collection of On30 Scale trains for sale is on eBay. Below are the listings for 'stock car'.

ON3 GRANDT LINE STOCK CAR KIT
ON3 GRANDT LINE STOCK CAR KIT
$25.00
Time Remaining: 1d 12h 45m

Other On30 Scale train items recently purchased through this site:

ON3 GRANDT LINE STOCK CAR KIT