If I get pulled over on the highway, I'm not going to want to have to get out of my car and pull out my spare tire just to get to my proof of insurance. I've seen too many cars on the side of the road get smashed into by some idiot not paying attention. I'd rather not risk it
There's also a cubby behind the passenger seat. Have you considered this location for some of the stuff you keep in your glove compartment?