Question about bass reflex housing

Servus, I would like to add a new sub to my E46 Limo or 2. Now I have decided to BR but I don’t know exactly if that’s what I’m thinking. Everywhere I see a BR case, the sub and the pipes always look in one direction and I want the subs to look in the trunk and the pipes (1 or 2?) through the ski bag opening in the interior. Is that possible? Please don’t laugh now….if you see the drawing. I don’t know about BR. As a sub I would take 2x the Radio 12 from Audio System. And I have the Eyebrid 1Y2 500 with 350 RMS. Do I need 2 power amplifiers for two subs? Thank you very much, Serkan