"Egon Evertz, the enthusiastic amateur Porsche racing driver from Solingen, wanted to produce individual cars to represent the ultimate in driving experiences. With a team of specialists to carry out his ideas, he had Porsche customers in mind, but the first car he made was a two-plus-two VW-based sportscar called 'Evex 1'.
The plastic coupé was built on Volkswagen chassis and running gear, including a modified 2-litre engine which produced 120 bhp. It was 155½ in (3,950 mm) in length, 45 in (1,120 mm) high and weighed 1,765 lb (800 kg), the top speed being 125 mph (200 km/h).
Despite Evertz' optimism, 'Evex 1' never got beyond prototype form (...) Egon Evertz did not manage to join the ranks of recognized car improvers."
I've got a rear view picture as well. I'll see if I can get around to posting it later. So, this one was not Porsche based, but it was from the family, so to speak.