The STE Ibwrong's post is referring to is the Pontiac 6000. They introduced the Special Touring Edition as a trim level in '83. Despite not being the flagship of the Pontiac line up, they would end up receiving all the high tech gadgetry for the next several years. The last year for the 6000 STE was '89, with only 1376 being produced, ALL of which came with standard full time AWD. Starting in '90, the STE moniker was moved over to the then more popular Grand Prix.
The STE package for the Grand Prix was produced from '90 - '93. It was the premium package for the sedans, complete with STE specific wheels, seats (10-way driver's side power) and center console lid covered in the controls for the seats, 8 speaker system (including 6.5" AND tweeters in the front doors), specific door panels, etc.
In '90 only, 1000 of the 5773 STEs came with a McLaren Turbo version of the 3.1L. They were only available in white or maroon with key colored rims, and got the same functional heat extracting hood louvers as the 2-door McLaren Turbos. Outside of the hood, and the "Turbo" under the STE badges, there is no distinguishable feature between a turbo and non-turbo STE. The turbo 3.1 was dropped all together after '90. The n/a 3.1 became standard with the 3.4 DOHC as an option.
Dubbed TGPs, the 2-door Turbo Grand Prix was only produced in '89 (751 made) & '90 (2749 made), and were only available in red and black with the vast majority coming in a camel interior. Only a handful got a light gray interior. While the '88 Olds Cutlass Supreme Pace Car was the first car to introduce HUD, there were only 250 of those produced, so I consider the TGPs to be the first "regular production" car (if you can call them that) to get HUD. A slightly trimmed version was then available for all GPs from '91 - '93, before the interior redesign in '94, which saw the first "under the dashpad" version HUD. Again, nothing on a TGP signifies that it is a McLaren project, though they are ever so slightly easier to distinguish from a non-turbo model vs. the STEs. While the B4U body cladding package is almost identical, the TGPs were the first to get the cladding (originally built by ASC, thus "ASC/McLaren Turbo Grand Prix"). Consequently, they were the only GPs to have the same body cladding that the '91 - '93 GPs would be available with, but still retain the composite headlights instead of using the "mini-quad" headlights found on the later GPs.
Any other questions?
