Lotus Omega/Omega Carlton
This crazy menacing sedan is virtually unknown in the USA. Despite this, it was a model by GM’s subsidiary Opel in Germany and Vauxhall in the UK. It once claimed the title of the world’s fastest four-door. Introduced in 1991 and discontinued in 1992, Omega Lotus was Opel’s rear-wheel drive luxury model tuned by renowned British sports car maker Lotus. It was given a turbocharger on top of an already powerful stock six-cylinder engine (via Auto Zine).

The 3.6-liter six delivered 377 HP, which was massive for the standards of the day. The performance was thrilling as well. The 0 to 60 mph run was over in just 5.2 seconds and the top speed was a record-breaking 177 mph. Lotus did the finishing and fine-tuning of vehicles produced and delivered by Opel. The body kit, spoiler, and unique details were all installed in England. Despite being very fast, the market didn’t respond well. Opel and Lotus made only 950 models, which are valuable classics today.