Is there a specific used car for sale right now that you're looking at? If so the best thing is to bring your bike when you go to test drive it so you can make sure it will fit.
Also if you dig around on the internet you might be able to find the specs for the older model. When I bought my car (2007 Prius) I was able to find details on the interior dimensions online before I went to the dealer to test drive.
- Gray 2010 carbon WSD road bike, Rivet Independence saddle
- Red hardtail 26" aluminum mountain bike, Bontrager Evoke WSD saddle
- Royal blue 2018 aluminum gravel bike, Rivet Pearl saddle
Gone but not forgotten:
- Silver 2003 aluminum road bike
- Two awesome worn out Juliana saddles