I think this xover came with your comp set
http://www.hertzaudiovideo.com/Doc/pdf_2W20.pdf
your car door is easy to remove, you should have a couple of long srews & clippons,
just find the srews & pull the panel off, just dont lose none of the clippons.
I'm sure the shop mounted the passive some place on the inner door.
yes your comps are passive,
yes phil collins is a good choice as well, do you have that CD???
passive & active are different set ups, with most passive xovers you'll have a adjustable swicth for the tweeter only, that switch help with balance of the car environment.
some people like the tweeter to sound really bright so they go up + db's & some people like there tweeters a little softer so they do 0 or - db, which help to balance everything out.
since you spent so much money for your toys you should learn how to use them, don't depend on someone to do it right for you.
give it a -db's or +db's
have you ever thought about going active???