Josh - Normally clipart does not and cannot be traded or "loaned", unless it was designed by the person that is giving it away. These things fall under copyright laws, and in some cases can get very serious. (Up to $250k fine per violation of the law)
I mention this because you are new and young, and now would be a good time to learn this stuff - before you get jammed up.
Now to the solutions to you quest.
1. Possibly someone has something they designed, which gives them free reign to do whatever.
2. Fred has a website (Express Clipart) where you can buy individual pieces without having to buy a complete collection.
3. The best solution, and even practice, is to take a picture of a cart - draw an outline - scan it in to your software - edit your nodes (clean-up) - and the end result is that you just made you very own piece of clipart.
Number three is not hard to learn but does require lotsa practice.
Lastly, a word to the wise....99% of all clipart/artwork on EBay IS illegal.
I use alot of JRG Media's clip art for racing art. They have a great assortment of good racing art. I looked in my catalog and they have about 50 pieces for kart racing. They have enduro's, sprints, karts with fairings and karts with body's. When I bought my collection I got it from EBAY. You can try the web site for them www.jrgmedia.com. Easy to deal with and JRG's ebay auctions were quite abit cheaper than his web page. I bought the MEGA collection and have not regreted it once. Hope this helps.