G-Power BMW M4 GTS
The folks at G-Power have long been in the business of developing tuning packages for BMW. In its history, the firm has worked its magic on a number of products—most famously the M3, and most recently the M4. This time, they've taken hold of the BMW M4 GTS, and boosted it up to chthonic levels.
Adding a B-Tronik 2 V3 upgrade to remap the engine was just the jumping off point. Toss in a pair of new turbos with bigger turbines, and the final product sees an increase of 115 horsepower and 118 lb-ft torque over your run-of-the-mill, stock GTS. Total output sits at 615 horsepower and 560 lb-ft torque, making it one of their most potent products to date.
Making sure to get rid of that pesky 190 mph speed limiter, the G-Power M4 GTS will speed well north of 200 mph, should you feel so inclined. There's also a catalyst-free exhaust and lightweight, forged, 21-inch wheels.
The total package comes out to $18,769 on top of the base GTS' already high list price ($133,205). Finding that base car will be your biggest challenge, though, considering all 700 units of the M4 GTS sold out before they even started production.