No. This grill in question WILL NOT fit a MY10 bumper as this grill is for older models a3's
Xenonz do facelift rs3 grills for 2008+ cars so if you have bought this one, it is the wrong one and you need to get a 2008+ one.
Audi A3 TO RS3 Front Grill S3 Gloss Black UK Stock Optic Pack | eBay
thats the one i bought.. i hope im set with this grill