Before searching for a car under 300 dollars, you must first understand what $300 car means – it won’t be just used car. Mostly they are old and in very questionable condition, so don’t get your hopes too high. However with luck and spending some time it is possible to find relatively decent car under 300$, which will be good for fun driving with friends (but don’t go on the highway) or for spare parts.
If you have a chance to get more money I would recommend reading about 500$ and 1000$ cars, otherwise keep reading this article.
Find cars under 300$
If you feel comfortable on Internet, you can try online auctions and best one of course is eBay. See eBay listings under 300 dollars:
Otherwise you can use auto junkyards and used car lots, however for so low prices great ( I think the greatest) place is Government auctions. In short, these are auctions when various Government agencies are auctioning seized&surpus property, including cars. Prices usually are 50-60% off the market value, for cheap cars sometimes even 80-90%, so if you’re lucky decent car under 300 dollars IS possible. And it won't be wreckage! Read about Gov auctions.
Car for spare parts
If you want car for spare parts, you should know what parts exactly you need and when browsing cars look for them. For 300 bucks you can’t expect all parts to be in good condition, but if you spend some time you can get needed part & other stuff cheaper then buying just one part. Plus you have other parts which in worst scenario will be welcomed in scrap metal exchange.
If you don’t feel 100% confident about cars, take someone with more mechanical experience, so you don’t loose money!