I did an exterior only on a friend's red M3 the other day. The car was so bad it looked orange! Apparently, 90% of the passenger side of the car was coated in brake dust, and the finish felt like sand paper as a result. I washed, clayed and used Meg's SMR with a Meg's red pad on my PC, then put a coat of Moosewax on it. He was very happy with the results. The clear coat on the car was so filthy, I had to throw my Clay Magic bar away after I was done - it was totally brown!!!
Before:
After:
Had he been willing to spend a little more, I would have done a middle step between the SMR and the Moosewax, but he was happy with the end result and wanted me to finish up.
Before:

After:

Had he been willing to spend a little more, I would have done a middle step between the SMR and the Moosewax, but he was happy with the end result and wanted me to finish up.