i got several questions

i got a '01 a4 1.8tq Avant and its got the bose package

the driver side door speaker is blown!!!

and need to find a new bose speaker

several questions

1) what size speakers are in the front? rear?
2) where the hell is the sub located?, tried finding it
3) where is the amp located thats powering the speakers and sub....
4) whats the max power handling can these babies handle
4a) i have a clarion 450 (100w RMS x4) that i want to know if i can use instead of the stock bose package for some serious sound... but want to know if it can handle it
5) want to put in my 2x 10" JL audio box n amp and want to know whats the best way to send power to rear and how did you guys wire it up??...
[edit] 6) how would i know if the car came pre-wired for a cd changer? where would the wire be located? [/edit]

thanks!!
sorrie for all the questions, just got the car last week, traded in a 02 subaru impreza 2.5TS (sports wagon 165bHP 166bTq) for a 2001 a4 1.8t quattro avant (170bhp 166btq)
the a4 pushes me in the seat, feels like it got 200+ horses in it