Go to the track and watch the kids having the most fun and the least time on the bench repairing. The cars they are using are probably name brand with a healthy access to spare parts without having to resort to and wait for mail order. I am not a car/truck guy but I am a long term RC Aircraft flyer who has built/setup more than a few cars/trucks for the kids of friends and relatives. For ease of build and repairs as well as availability of spare parts and fantastic upgrades as the skill level gets better its hard to beat the Traxxis line of products.
https://traxxas.com/products/showroom
Dennis