hey .. i've researched travel guitars for ages. since i travel a lot around the world. and i must say all the travel guitars have serious drawbacks,, be it tone... cheap build, or many are great ...like the company traveller" makes about the best sounding ones on the market but you'll have to import em.....the martin backpacker looks great on paper but is a very awkward guitar to hold...... if you sit and play it's useless... the others like siilent guitars are lovely they the standard yamaha mid ranged necks with pickups and effects onboard ... but it's gonna need a small amp... cos unless you wanna play through headphones ...which really is so irritating .... and means you only ever play to yourself and before you buy a yamaha silent guitar .aria make them too very similar but they even shorter in length cos they managed a clever design for the tuning pegs so it's cthe whole length of the headstock shorter than a yamaha go to aria website and look at "sinsonido" guitars under their guitar type listing ....
http://www.ariausa.com/guitars/as100s.html and they are available locally ... i seen em played live already ....
what i would recommend is finding the small bodies acoustics......... that have very narrow bodies ........ the baby taylor or preferably the big baby taylor would be nice...... and in the cheaper ranges there's some nice tanglewood acoustics that almost have narrow bodies almost like a semi acoustic (335) which are audible unplugged but flat so easier to carry....... and i know you prob want steel string but tanglewood make a nylon with a narrow neck and thin body and i think a shorter scale,,,,,,,,,, and last i saw you could get em for 2K or less with discounts......
and if you only want a guitar to travel in car with........ and not a plane.. forget the case.... the case takes up the room i bet you could take an acoustic and slip in in somewhere without a case...... even just wrap it in a towel.... and they make acoustic these days with quite small bodies.......
this is a very difficult choice to make......... good luck with it ... and hope you find something that works for you .......
let us know what you decide on
peace and light
keira