Questions about adding a BT capability (Swing unit, MaxiDOT, no MFSW)

Hello,

I was unable to find answers to my questions, so I decided to create my own thread here.

I am currently owning a Mk2 Elegance Fabia and I bought it with preinstalled Parrot HF. I decided to get rid off that and instead try to fit in the OEM version of Bluetooth and Handsfree.

The parts (BT Unit, Microphone and wiring) are already on the way and I am currently searching guides on how to connect that together.

Will I be able to fit the unit under the passenger seat when I have the storage boxes under the seats? I feel like there is not much space.. If no, since I haven't seen the size of the unit yet, will it fill behind the Swing radio?