There is a little secret that lies in the height of 5,000 ft. and 10,000 ft.. If you reach 5000 ft., you will be told to go back by 'Mr. Dog' and will be given $5,000 every time you come this high on load of your save. This could be exploited quite alot, but it requires a good engine though. At the height of 10,000 ft., you will be given a flying cross by 'GOD', just like the one the rainbow colored alien ship gives you. It's supposed to be an angel-like cross, unlike the devil-ish cross. This reduces the damage done to the AATV.