Like they did with ZL1 it appears that the boys at SLP have gone and acquired the rights for the 'GNX' nameplate...and they intend to use it.
This is the first rendering of the SLP GNX. This Regal-based sport sedan is looking to be the GS Buick should've built. SLP says that this one should crank out "more than" 300 horsepower (up from 270 on the GS) and, if this rendering is to be believed, will actually look special. (Note: the Regal itself looks very clean, but the GS is, well, pretty bland for a sporty model.)
We should know more about this one in the coming months, but if you've got any interest you should hit up SLP sooner rather than later. However the final product turns out, they're only building 500 of 'em.