You could use any vehicle to collect scrap in. I have seen people with small hatchback cars full of scrap metal. Depending on what you are trying to achieve, you could use anything from a bike with a trailer (pictured) to a large truck with a crane.
The most important thing when it comes to carrying any sort of load in or on any vehicle is making sure the load is held firmly and securely in place. The best method for this would be rope or ratchet tie down (also pictured).