According to the Bently, the serial # says I have a 535is. The only performance item not seen on all 535's is the LSD (not the Timothy Leary kind) and the 5 speed. Most is's show a rear spoiler and a front valance like the M5. Or have most people upgraded to the M5 style body stuff? The owner's manual doesn't give any specifications for an "is" - only gives specs for 528e, 535 and M5. I did pick up a 535is/M5 valance at the junkyard on friday though, $30 with fog lights. Someone got the easy part before I got there, the rear deck spoiler.