When I had a trunk rack for my bikes I used two u-locks to secure the bike to the rack. However that was more to make sure the bike didn't fall off the rack. I never left the car unattended with the bike on the rack.
- 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