changing page url / parent post

Hi guys,

I have a website where I am displaying “makes” and “models” of a certain type of product. (Not using a shopping cart solution, as there won’t be any purchasing going on)

Using Advanced Custom Fields and custom post types, I’ve made a “make” custom post type, with a bunch of custom fields for it (price, photos, etc), and then a “model” custom post type, with custom fields for it. I am using the “relationship” field in the Advanced Custom Fields in order to assign each “model” with a “make”.

The only thing is, WP puts the URLs at:
mysite.com/make/(makename)
and
mysite.com/model/(modelname)

(as in, the word “make” is actually in the URL)

For SEO and organizational purposes, I would like the models to be at:

mysite.com/(makename)/(modelname)

In the part in the admin area, at the top of a post, where you can edit the URL, it only lets me edit the part after “make/” or “model/”. Is it impossible to have mysite.com/(makename)/(modelname)? Is there anything I can do in the PHP or some custom settings or something?

Thanks!
Heather