And yet back in 1990 Vauxhall had no problems selling every Lotus Carlton they could produce.
They did have problems shifting them - so much so that the last 150 cars, most/all of them right hand drive, were never actually built. There were supposed to be 1100 LC/LO's built, but in the end only 950 were. Production only lasted a little over 18 months (spanning 3 model years - chassis numbers L, M & N) but it took almost 5 years to shift all the cars bult. There are stories of the grass infield at Hethel being used as a car-park for unsold cars - which may go some way to explaining certain rust issues.
Some were offered to interested parties who had gone in for a new GSI at the GSI price
I've not heard that, but the last few UK cars were 'loaned' to loyal Vauxhall customers for extended test drives (several weeks) and then at the end of the loan they were offered the car's as ex dealer demonstrators for between £20 and £25K. This would have been 1994 ish. For comparison I first looked to buy a new Omega Elite in 1995 and they were pushing £30K then.
176 MPH around Nardo though. 
According to the test team that figure was the lap average. Peak speed was over 10 MPH north of that, but there were concerns about overheating the tyres on the banking Then the fuss in the papers blew up, and all mention of speed was discouraged from on-high.