This one’s a bit tricky, because the Trofeo appears to be technically a trim level of the Toronado. I’m sure some people list them as just “Trofeo” without the Toronado though.
For now your best bet is probably to choose “Any Oldsmobile” and then enter Trofeo in the keywords box. We’re planning to revamp how we handle model names in the near future, so will keep this in mind then!