Some examples of valuable cars made for the 1991 model year include the Mercedes-Benz 600 SE, Porsche 928 GTS, Porsche 968 Coupe and Acura NSX Coupe. Each model is valued between $50,000 and $120,000, although certain non-production models, such as the Mercedes-Benz C112 Concept, can be worth millions.
One of the most valuable cars made for the 1991 model year is the Mercedes-Benz 600 SE (W140). As of 2015, it is valued at $120,000 and has a top speed of 155 mph with 408 horsepower.
Estimated at $90,000, the 1991 Porsche 928 GTS can reach a top speed of 170 mph with 350 horsepower. The similar 1991 Porsche 968 Coupe is worth around $70,000 and boasts 240 horsepower with a top speed of 158 mph.
In 2014, the 1991 Acura NSX Coupe reached an estimated value of $52,300. Considering this model sold for $60,600 when it was first released to the showrooms in 1991, the NSX has done well in holding its value.
Of course, these are vehicles that, while hard to come by, are far from an impossible find, which is one reason only one of the four cars barely reaches a six-figure valuation; there were plenty of them made. However, experimental or concept cars that never make it to production can be far more valuable. The 1991 Mercedes-Benz C112 Concept is one such model and is estimated to be worth between $3 and $4 million.