Another tire question

I have been searching around for a set of tires to put on my second set of stock rims. As we all know the fronts are 245/40/18 and the rears are 275/35/18, but will other larger sizes fit on the OEM rims and also clear the wheel openings?

Finally does anyone have experience with the tires outlined below? They seem very inexpensive, have a long treadlife and come highly recommended by others who have used them on cars other than the M5. As usual it sounds to good to be true...

<TABLE cellSpacing=0 cellPadding=0 width=630 border=0><TBODY><TR><TD width=630 colSpan=6 height=10></TD></TR><TR><TD vAlign=top width=250><TABLE cellSpacing=0 cellPadding=0 width=250 border=0><TBODY><TR><TD class=bold width=250 colSpan=2> </TD></TR><TR><TD width=75> </TD><TD class=bold width=175>g-Force Sport</TD></TR><TR><TD width=75> </TD><TD class=textTight width=175>Great dry handling and affordability. Z-speed rated.</TD></TR><TR><TD width=250 colSpan=2 height=8> </TD></TR><TR><TD width=75> </TD><TD class=bold width=175>275/35ZR-18 95W RBL</TD></TR><TR><TD width=75> </TD><TD class=links width=175>Reading the Tire Size</TD></TR><TR><TD width=250 colSpan=2 height=13>

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</TD><TD width=175>$160.00 ea.</TD></TR><TR><TD width=250 colSpan=2 height=8> </TD></TR><TR><TD width=75> </TD><TD width=175></TD></TR><TR><TD width=250 colSpan=2 height=20> </TD></TR><TR><TD width=75> </TD><TD class=links width=175>(Start a New Search)</TD></TR><TR><TD width=250 colSpan=2 height=3>

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</TD><TD class=demi width=175>Specifications:</TD></TR><TR><TD width=75> </TD><TD class=solid width=175>Treadwear: 340</TD></TR><TR><TD width=75> </TD><TD class=solid width=175>Traction: A</TD></TR><TR><TD width=75> </TD><TD class=solid width=175>Temperature: A</TD></TR><TR><TD width=75> </TD><TD class=solid width=175>Speed Rating: ZR</TD></TR><TR><TD width=250 colSpan=2 height=20> </TD></TR><TR><TD width=75> </TD><TD class=demi width=175>Show me:</TD></TR><TR><TD width=75> </TD><TD class=links width=175>• Comparable Tires</TD></TR><TR><TD width=250 colSpan=2 height=5> </TD></TR></TBODY></TABLE></TD><TD width=20> </TD><TD vAlign=top width=300><TABLE cellSpacing=0 cellPadding=0 width=300 border=0><TBODY><TR><TD vAlign=top width=300> </TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>