At times you have an old car that you need to get rid of. It might not work anymore or you might have upgraded and don't need the old one anymore. Sometimes old cars are actually worth more sold for parts than as a whole unit that is not functional. You might be able to sell that old car for parts and make more money off of it.
When should you sell the parts as opposed to the whole car?
If you drive a popular model that many people are still driving this is very helpful. Someone will need parts for this so they will be easier to sell. If it's an obscure model, this is more difficult.
The parts could be worth more than the whole car. Check to see the prices of the parts and see if you could make more money this way.
If you don't need all the money at once, sell it for parts. You will get your money gradually but many times it will be more.
If you have the time to sell each one individually, you could consider doing it this way.
How can you sell parts easily?
List the parts online. There are many auction sites that you can use to list things. Be sure that you use pictures and even video to give the potentially customer more information. The more they see, the more likely that they will buy.
Use sites like Craigslist to find any local buyers. It's free to list here and you could get someone interested in more than one part if they are already buying one.
Take everything else to the junk yard that doesn't sell. You can get some money of out it this way and be done with having to deal with the car. Shop around and see if one will give you more than the other in town.