How to load a paintjob file on a car that you don't own?

In Forza 6 design mode, it lets you switch to any car and then load paintjobs and work on vinyls. Even if you don’t own the car.

I can’t find how to do this in Horizon 3. So I’m unable to update my imported paint jobs from Horizon 2 and Forza 6… until I earn millions of credits to buy each car. Horizon 3 lets you paint cars, from scratch, without buying them (Design > Car Select > All Cars), but you cannot load any of your saved/imported paint jobs onto the car unless you buy the car. If you’re painting a car that you don’t own, the file menu only has “Share” and “Rename”, it doesn’t have “Load”.

Does anyone have a tip? Am I missing something? Thanks.

(I didn’t mean to paste this reply right here, and I can’t get rid of it)