One of my co workers at Disney did this, I’ve never tried it but every time I walked past their car with the cookie pan in the windshield I thought it was brilliant.

I think right now all of the Kindle e-ink devices can be jailbroken to be less restrictive, so if you have sources for DRM-free ebooks (Baen and a few other publishers and sites sell them) they’re a lot easier to use on the device you already have.