[quackbury]

I did a Search, and although it returned a lot of results, I couldn't find an answer to this question.

I just picked up a lease assumption on a 2015 35i for my son (my daughter has a 2015 28i xDrive). The 35i screams out for better tires, so I am thinking about storing the OEM RFT's in the garage till lease end, and putting on a set of non-RFT performance tires (we run dedicated wheels and snows in the winter).

He goes to college in Maine, so if I put non-RFT's on, he will need to carry a spare. What I would like to do is mount it under the luggage compartment floor, in the recess where the dividers live now.

The spares advertised on both Bimmerzone and Bavauto are 5.5" wide, and the dividers are 2" high, so I would have to raise the cover by another 3 1/2" to 4". I have no problem giving up the storage space; there should be plenty of room around the spare to fit in a jack, air compressor, tow strap, jumpers, etc. The mod would give us less space for other "stuff", and take away the flat floor when the rear seats are folded, but we can live with that. (We throw the Thule on whenever we need to carry a lot, anyway).

What I am considering is adding a 3 1/4 to 4" foam block, running the circumference of the "floor". It would have to be pretty well sealed, to keep sh*t from falling through the crack, and to keep moisture out of the electronics. (The OEM rubber trunk liner would sit on top, and should help in this regard).

So my question: this seems like such an elementary mod, that SOMEONE must have already done it. Or at least considered it. Any feedback, tips, or cautions? Thanks in advance.