Hi Gang, Still learning a lot about my CLK but still many unanswered questions. I have a really great sound in my car - It has the usual door speakers but also has a bose speaker (Possible Sub) under the armrest in the rear. Can someone confirm if this is a sub..? Also - do these cars have amps as mine really pumps it out. I don't understand a lot about the Merc systems yet but would like to know if it has one and if so where. Also whats the possibility of speaker/sub/amp upgrades..? Many thanks in advance.