American tuner Vorsteiner, as you know, already has a styling kit for the BMW M4 Coupe. But that kit is way to simple for a tuner with Vorsteiner’s reputation and expertise. That is why they are working on an extreme wide body version called GTRS4, to be unveiled at the SEMA show next month.

Vorsteiner BMW M4 GTRS4 will build on the success of the firm’s wide body E92 M3s which were among the widest and coolest tricked-out Bimmers in the world. The GTRS4 will get the same sort of wide arches and massive aero parts, but because the M4 is a more handsome car than the old M3, the end result is going to look much more spectacular.

The teaser shot released for Vorsteiner BMW M4 GTRS4 are not the revealing, but even so, they show some important parts such as the huge rear diffuser with some properly big tailpipes, the rear spoiler, the extra wide fenders, and the revised front bumper. Vorsteiner rarely does engines and interior, but we’d love to see this car equipped with bigger turbos and maybe a stripped-out interior!

Stay tuned for more on M4 GTRS4 in the run up to the SEMA show which begin on November 4.