This is an original RC10GT (tub chassis), they came with a black or blue chassis



This is the second version of the RC10GT (flat chassis), and a lot more common. They came as the RTR, the GT-plus, the Team kit, and the Factory Team kit.



This is the RC10 GT2. Notice how the chassis is a bit more narrow, and has a top deck.



Currently, associated makes replacement parts for the flat chassis GT, and the GT2. You can still find an abundance of parts for the tub chassis GT on ebay. Most the parts between the tub chassis and flat chassis GT are interchangeable. The GT2 mostly uses model specific parts.