Iso-game: char using objects

i am learing some iso tile base stuff at the moment. Thanx for your tuts: Kirupa and Tonypa.

But i have some problem.
I want so place some cars on the map.
The maincharacter must be able to use these car. getIN getOUT.
I donno how to do this.

My char is free to move in (x) an (y) direction ( not only from tile to tile) he’s not able to rotate.

Has someone of you ever build an complex iso game ? Maybe you can post or send me the fla with some text around it ?