The most family friendly Opel ever made, it had power for the dad, comfort for the mom and rattles for the kids... I owned a 1990 Superboss in South Africa in the late 90`s, damn that thing was quick, replaced it afterwards with another South African only Kadett, the mighty, if a little terrifying 200TS, you should look into that car, a true one off Torque Steer Terror of the streets!
My family had one but not GSI , my father bought it from Germany in 86, and sent it to Libya, we sold it in 2010. it was dark grey and 1.3 engine, 5 doors, sedan.