Space Saver Spare Question

[Ohmess]

Hi All --- e39 guy visiting from another forum here. I am thinking about a true dual exhaust for my beloved 540i6. This will entail modifying the trunk floor of my car so as to reduce the size of the spare tire well, and thus the loss of my spare tire. I'm thinking about a space saver spare, and I think the only one out there may be designed for the X5.

So, my question is, can anyone here provide me with the dimensions of the space saver spare that is available on the 4.8i?

Cheers.