Makeshift car rack for a short drive? I need to transport a bicycle down a highway. It'll be a ten-minute drive. The bike won't fit inside the car, though. Is there any way to mount/tie the bike to it?
Context: I'm going to be taking a public bikeshare bicycle to a car rental place, and then I need to transport the bicycle to the nearest bike share station. So I can't modify either the bike or the car.
It sounds like one of these situations where walking, at the sustained pace of 3 mi/h - 4.8 km/h will do the job.
Think about the time you will need to set-up the bike to fit in the car. Probably you cannot remove the front wheel from the bicycle, because they use special lock to avoid theft.
However, you face two solutions:

If you are fit to cycle, you are fit to walk or even run to the rental car agency. It seems weird, but hey, bike rental were a weird things until 5/10 years ago!
the bike will fit inside the car, at least partially. keep it in place with bungee cords, and use bungee cords to keep the bicycle in place, as well as those &quot;flat section ropes with metal hook used to move furnitures&quot; to keep the lid partially closed and the bike inside.

Take into account that the car will possibly prevent your gearbox to shift on a gear &gt;2 with the trunk open.
Every car has at least a couple of hooks inside the trunks.
What car are you renting? a Smart or a SUV? what bicycle is the bicycle? 20 inches wheels or 28 inches wheels?