I started my game in Mos Eisley. I rented a vehicle and decided that I wanted to travel to Anchorhead. I got to the square just north of Mos Eisley and decided that it was going to take too long. I went as far south in the square just north of Mos Eisley as I could but the cross terrain function isn't available. How do I get back inside Mos Eisley!!!
You can't get back into Mos Eisley because its terrain is rock, and that is on the terrain restrictions list of the U-9000. This is something of an oversight in the older code of cross terrain travel, it should be ignoring the terrain restriction if a city is built there (like the in-city code does). I've put you back in Mos Eisley. If you want to travel around more 'll swap your U-9000 for a vehicle with less restrictions.
On a side note, have you considered joining a faction?