RCknight, I have over 7 months of racing on my car and all the parts are still nice and tight. The stock composite diff outdrives show very little wear and that is with mod outdoors on asphalt, indoors on concrete and on carpet. The shiny cvds from the TC3 will work but I am not sure on the composite ones as they are longer and may hit the diff nut. I dont think there is really anything wrong with the stock bones. I bent one many months ago but it has held up great. As far as moving the batteries, that is one of the benefits of the car. The batteries are moved as far in as possible to keep the main weight down the centerline of the car. It is very important to balance the car out left to right though as it is very noticable if you have not done this with the car turing great one way and not so well the other way. It is a very adjustable car and small changes make huge differences on track. I have ran the delrin outdrives with 9 turn motors with no problems. For carpet I changed the chassis out for a SWEET PRP chassis kit that has a 3mm upper and lower deck as well as an adjustable rear wheelbase to allow for high bite carpet tracks so you can move the rear arms back to add more steering. Nice tuning tool.