Magnet interaction?? (Car Audio)

OK, so Im finally replacing the blown rear 6.5s (they were stock) with some sony XPlod ES ones

Now these are a bit deeper then the stock ones, so im getting lil things to raise them up, as the magnet will then be sitting right on top of the sub box, and my question is, will the magnets of the subs cause interaction with the XPlods? and if so, what can I do to magnetically shield them??