Sonic Adventure DX Director's Cut Cheats

Tails in Sonic's Speed Highway!
As Tails, go into Speed Highway. Go on the path the you'd normally take with Sonic. Once you get to the ramp that's above where Sonic would enter the building, get launched off the ramp and immediately start flying over towards the building that Sonic would enter to get to the next part of the level. Once you're in the building you should be able to see the ceiling for the part Sonic walks into. once you walk on a certain spot, you'll be taken to the 2nd part of Speed Highway where you're running down the building, except Tails will just fall down and eventually fall into the 3rd Area.

Now, notice that you still have the bar at the bottom of the screen that shows where you and Robotnik are with progression of the map. You'll be at the very start of the bar. You can get rid of that bar and give yourself unlimited time to explore the 3rd area as Tail if you die in the part where you fall down the building. To do this you simply need to get hit by a helicopter, then with out getting any more rings, get hit by another helicopter. You'll lose a lose, but then will appear at the beginning of the 2nd part of the level without a time limit!

Have fun exploring the higher areas of part 3 of Speed Highway as Tails!