Couple weeks ago spotted a nice low mileage 06 E53 4.8iS. It had couple M badges around. Dealer insisted it was X5M. I reminded him BMW did not make X5M until '09!
He was commanding 5K premium compared to similar offerings because of his damn M badges. I walked away.

One sure way to know is lookup engine which are all prefixed with "S"


Garage:
E53 X5 4.4i M62 born 2003-03-04
E90 325i N52 born 2006-03-28
F30 328i N20 born 2012-09-06

__________________
"better the devil you know than the devil you don't"
2003-03-04 E53 X5 4.4i M62 [SOLD]
2006-03-16 E53 X5 4.8iS N62s
2006-03-28 E90 325i N52 [TOTALED]
2012-09-06 F30 328i N20 (CEO's)