The only advice I can give is to make sure you go to a shop that is
permanent. I live in an area prone to lots of hailstorms and whenever we
have one guys come from all over in their vans and offer "too good to be
true" prices. They usually set up at small body shops and garages until the
work slows and go somewhere else. I had over 200 dents in my Town Car done
by my local body shop and it came out great. The hood and trunk were
aluminum, so they had to be replaced along with all the body molding and
plastic, but the dents came out great. The body shop used someone local to
do the paintless repair and the body shop warranted all the work. If I were
you, I would call a reputable body shop and ask who they use. Paintless
repair is like a lot of other things, you get what you pay for.

Ed