lancer wagon rear speaker upgrade?
 

Hi all,
has anybody out there upgraded the rear speakers on the lancer wagon (estate) 2008 Model CS3W?
If so, how hard is is? and what are the mounting size holes & depth have you got available?
I would normally just pull the trim, but they are large items running right around the sides of the rear seat & look like they need removal of the seats and seat belts just to check.
many thanks