Now you can call a taxi. Enter the cheat code 'taxi'. Tommy will call on the phone. He'll say, "Come here, you piece of shit!" The taxi will come to you. Please wait, this may take some time. When the car pulls up to you, do nothing, Tommy will get into the car himself. Arrows left, right, select the destination, the N key, the taxi will start moving, but your money will decrease a little.
Here is a visual video demonstration:
Installation: Taxi.cs file added to GTA Vice City/CLEO