New R8 V12 TDI thing is obvious choice.

But id get Banks Power to build me something badass like this...
www.youtube.com/watch?v=j2MmAJm_mhw

But with an engine etc more like the original Sidewinder, which went 222mph, road legal, reliable, 1300lbft, and even drove to the Salt Flats towing the big trailer with all their equipment in it...