Head unit is Pioneer DEH-3450. My former bicycle's helmet rear mirror its the way I found to rebound steering wheel control signal. If you know a better solution please advice.

Pioneer CD-SR77 Steering Wheel Remote Control. It operates well after the little mirror trick.

Pioneer TS-C1653 6.5" Component Speaker Package. Used as front speakers. Bass are installed at doors in original position and factory grilles, crossovers under the dash and tweeters at top of pillars. They have a very clear sound.

Pioneer TS-A6895 6"x8" Two-way speakers are at the sides of rear seat replacing factory ones and also conserving original grilles.

Amplifier: Logic Soundlab CPX840 Four Channel.
It is instaled at the back of subwoofers box.

Pioneer TS-A6995 6"x9" Four-way speakers. Installed in removable additional boxes at cargo area.

Pioneer TS-W304F 12" Free Air Sub-woofers. Installed in removable box at cargo area.

Subwoofers and additional speakers boxes.
They are easily removable if I need all avalable cargonspace and also I can use them in my other car.