I stumbled across a 1/18 scale model nearly identical to my father's and it brought back so many memories. At 6'3" and 260 he didn't exactly have a lot of room but absolutely loved driving that car.
I did a search for other Opels and found a few gorgeous ones and some not so.
The "I'm not going on a date any time soon":
This is probably the closest to what his looked like:
Rattled/resonated, metal on metal when you closed the door, tinny sounding high revving modified engine, no power steering and loved cruising around with dad in it. I think his was a 69/70. My favorite part was when I was allowed to roll the headlights.