Denso Spark Plug 5309 Fits select: 2006 BMW M, 2007-2008 BMW Z4

Denso® factories are QS9000 and ISO9000 certified worldwide, just one of the many reasons why zero defects for parts produced in the millions is a reality for Denso. A recipient of the prestigious Deming Award for quality in 1961, Denso spent over five decades perfecting technology and processes, a claim that few automotive manufacturers can make. Denso First Time Fit™ products — including A/C compressors, starters, alternators, oxygen sensors, ignition wire sets, fuel pumps, cabin air, oil and air filters, wiper blades and more — are products built and tested to OE-standard offered for the aftermarket by Denso. Each of these products is precision-built for exact replacement so you don't have to worry about doing the same job twice.