il Conte wrote:
But how to fix it under the seat?
I think there was some kind of mounting kit, a plate which holds the amplifier with some holes for screws or something like that.
Here, taken from the accessories pages:
"...Volvo Part Number:
* Chassisnrs up to 567600:
o HA 4140 = 1373082-5
o
Fitting kit = 3453527-8
o Cable = 1373086-6
* Chassisnrs 567600 and onwards:
o HA 4140 = 3533177-6
o Fitting kit = 3453527-8
o Cable = 3464008-6"
And
"Height Adjustable Seat
* For optimal ride comfort.
* Seat is adjustable in height over a range of 42 mm.
* Available for left and right.
.....
* NOTE: height adjustment is not possible in combination with amplifier under passenger's seat."