My car had both. I am guessing that they picked up what ever was on the floor and used them when assembling the car. My other guess would be that the machine screw threads were buggered up so they used a self tapping screw to fix it. Scott Mueller 002981 RNDOLA -----Original Message----- From: Martin Gutkowski [mailto:webmaster@xxxx] Sent: Saturday, July 05, 2003 2:35 PM To: dmcnews@xxxxxxxxxxxxxxx Subject: Re: [DML] rear Light screw fixings Having thought about this, my reply was perhaps a little hasty. This mail is more of a question really: Why do some cars use self-tapping screws to mount the light clusters, and why do some (like mine) use M4 machine screws? Martin