Here's what I did to accommodate a full sized spare- I cut the under-floor storage tray as seen here with an oscillator, because even with the foam piece that lives in the spare wheel well that holds the various electrical relays and modules removed, the well is not deep enough to hold a full sized wheel/tire below that tray. So with tray removed, I should be able to fit the real wheel and be able to shut the floor pieces like normal. The wheel pictured is the donut, I haven't put a tire on my full sized wheel yet but will put a picture up when I do. NOTE: I got my matching 17x7.5 bmw wheel for $36(!) from a wrecker called all foreign auto on ebay.