When you take the vehicle to get it regoed take a copy of that EMEI and a printed off picture(3 copies) of a workshop vehicle to prove that they were standard fitting, as Transport will want 1 copy to staple to the paperwork, the other copy you keep,to prove that you submitted it, the 3rd you carry with you in the vehicles paperwork, so that Mr Plod won't try to book you for an illegal exhaust system
the same advise goes to those owners of FFR's with front exhaust.
All this saves you getting a fine and ?? demerit points
Went through all this a few years ago with a S3 FFR