The FIAT based Abarth 750 GT by Zagato features the typical double-bubble roof. Rather diminutive in size, it packs a lot of power per kilogram in original guise. Imagine a Porsche flat six with a set of turbochargers in it and… you should be scared as hell by the power-to-weight ratio! Due to fitment issues, this fortunately isn’t possible in reality. Otherwise you would definitely need to register it as a weapon at your local DMV. 😉