My 2 cents....
Keep the logo single color. Makes it more versatile.
If you're using PhotoShop, can you use the invert filter so we can have both a black and white version?
The 'X' was good representation of the interstates on the first one, maybe see if it works with miniature interstate logos...like a map
I like the crest/emboss effect
I like the font you used on the version with the stars, though I'm not sure it will work with the 'X'
I think a jeep size slightly larger than the version with the stars and slightly smaller than the last few versions would be perfect
Anyway you can remove that front license plate?
Keep them coming, they look great!