To anyone who isn't aware, there is a huge world of car hacking. There is of course the basics like getting an expensive air filter (pointless), and it goes all the way up to welding up your own custom car. The more common mods are things like tuning your suspension, replacing your engine with a more powerful one, or upgrading your differentials. It takes a wide range of skills, including welding, machining, panel beating, plumbing, and electrical. You can very easily nerd out on this.