My stomach is still tied in knots after my first and last landing at Aspen in a Hawker over 25 years ago and I the SIC. I think we made a left pattern to 15 it seemed like if I reached out the window I could grab pine branches.
Perhaps you can call the NBAA or the local FBO could hook you up with a local who has the KNOWLEDGE.
So are you babysitting for the Mustang's owner? If so use a little physchology and tell him/her it's always better if the instructor wrecks the plane.
Watch out for density altitude!!!!
and Good Luck!