This filter will fit in place of the original Mini Cooper Panel filter. all you need to do is un clip the air box, remove the original restrictive paer filter and drop the K&N high flowing air filter (33-2270) into place.  No modifications to engines computer or anything else required. K&N Air Filters come with a life time gaurantee and are washable and resusable.

33-2270 Panel Filter Specifications
Height: 1.063 in (27 mm)
Outside Length: 10.688 in (271 mm)
Outside Width: 6.375 in (162 mm)
Weight: 0.92 lb (0.42 kg)

OEM Mini Air Filter Part Number
BMW 13721491749
Mann-Hummel C2851
Ryco A1599

K&N 33-2270 fits Mini Cooper S:
2008 MINI COOPER S 1.6L L4 F/I - US, Convertible  
2007 MINI COOPER S 1.6L L4 F/I - Convertible  
2006 MINI COOPER S 1.6L L4 F/I - All  
2005 MINI COOPER S 1.6L L4 F/I - All  
2004 MINI COOPER S 1.6L L4 F/I - All  
2003 MINI COOPER S 1.6L L4 F/I - All  
2002 MINI COOPER S 1.6L L4 F/I - All