What is the difference between the Sport premium and the x drive 30i

Standard equipment on the xDrive30i includes 18-inch alloy wheels, automatic adaptive xenon headlights, cruise control, rain-sensing wipers, a panoramic sunroof, dual-zone automatic climate control, 10-way power front seats with driver memory settings, a power tilt-and-telescoping steering column, vinyl "leatherette" upholstery, wood interior trim, the iDrive electronics interface and a 12-speaker sound system with a CD player, HD Radio and an auxiliary audio jack. PREMIUM package options : Numerous option groups include the Premium package, which adds auto-dimming mirrors, a power liftgate, BMW Assist telematics with Bluetooth and -- for the xDrive30i and xDrive35d -- leather upholstery. The Sport Activity package adds 19-inch wheels, dark exterior trim, sport seats and a sport steering wheel. An M Sport package builds on the Sport Activity by adding body-colored M exterior parts, an adaptive suspension, a sportier steering wheel, aluminum roof rails and a higher top-speed limiter.

http://www.edmunds.com/bmw/x5/2010/#overview-pod --- here's where I found that info.