Lipo fitment is no issue on the TB03. You can fit anything in there. The battery strap hold down posts can be unscrewed to different heights to compensate for differences in lipo case height. I've used SMC 5200 and Thunderpower 5000 lipos and have plenty of room.
TB03 is a great car. And if you ever want to go and race it, you'll have a car that people hate to admit they got beat by
The sealed drivetrain design is awesome. I recently made a rally car out of a spare TB03 I had....driving it though the dirt, jumping off things, driving down gravel roads and no issues yet....its been really fun to mess with. So driving it on the public streets near your house you won't have any issues.
Its a tough car, you'll enjoy it.