I had some time today to weigh some *stock* parts from the M3 E46 2002 euro version.

Seat (power seat w/ heater, mounting slider, head rest, belt pretensioner, leather, passenger side, no first aid kit) 29kg
Silencer (including 4 exhaust tips) 25kg
Front calliper 6kg
Rotor (including mount hat) 8kg
80Ah battery 21kg
Flywheel 11kg

If somebody wants it can convert into lbs.

Maybe we can make a list of stock items and how much they weigh, handy for those that want to reduce weight of their cars...

This would make a good sticky, since this question is brought up often. 1kg = 2.2lbs.

the exhaust is around 55 pounds.

I'm not sure if there are any differences between the Euro version and our version in weight perspective. But those numbers do seem pretty right if you convert them to pounds.

Our cars would be so quicker if those parts didn't weigh as much.

I was bored, so I ran the conversions:

Seat (power seat w/ heater, mounting slider, head rest, belt pretensioner, leather, passenger side, no first aid kit) 29kg = 63.8 lbs.
Silencer (including 4 exhaust tips) 25kg = 55 lbs.
Front calliper 6kg = 13.2 lbs.
Rotor (including mount hat) 8kg = 17.6 lbs.
80Ah battery 21kg = 46.2 lbs.
Flywheel 11kg = 24.2 lbs.

This would make a good sticky, since this question is brought up often. 1kg = 2.2lbs.

Already been done:

http://www.m3forum.net/m3forum/showthread.php?t=44266