My son's girlfriend bought him a backpack designed for a pet to ride in. It also acts as a small tent but with mostly a mesh top. His cat is strange, we didn't know how he'd like it (if at all) and told him to never force/ coerce his cat into it.

First day, in tent mode, the cat wouldn't leave it! He loves the big clear side and the holes he could stick his nose/paws out through.

My son gave his cat over a week to get used to it before even trying to take him on a walk with it. The cat jumped in it without issue and didn't mind being on my son's back. For the first 30 seconds he sat there looking around. He then layed down, got comfortable, and enjoyed the ride!

He asks for walks now. It probably helps we have a lot of trees with squirrels and birds in them.