This is a list of test results from serveral different sources each different, but it should give you a prospective of actual performance.

Road & Track "May 2004"
3.0L Z4 BMW with SMG Transmission.
0-60 MPH = 5.6 seconds
1/4 mile (0-1320ft.)= 14.2 @ 99.1
Braking 60-0 MPH = 108 ft.
Car & Driver Annual Road Test 2004
3.0L Z4 BMW with 6-Speed Manual Gearbox.
0-60 MPH = 5.3
1/4 mile (0-1320 ft.) = 14.0 @ 99.0
Braking 70-0 MPH = 158 ft.
Motor Trend "January 2004"
3.0L BMW with SMG Transmission.
0-60 MPH = 6.1
1/4 mile (0-1320 ft.) = 14.5 @ 96.6
Braking 60-0 = 112 ft.