Utility
The BMW 328 and the Volvo C30 can accommodate the same number of passengers.
There's no clear winner between the BMW 328 and the Volvo C30 regarding hauling capacity.
Dimensions
The Volvo C30's tank is roughly the same size as the BMW 328's, though the BMW 328's is a little larger.
The Volvo C30 and the BMW 328 compete for the same parking spaces.
Convenience
You most definitely won't have to visit your friendly gas station more often with the BMW 328 than with the Volvo C30, because both offer comparable ranges.
Cost
The destination charge is a standard charge for transporting the vehicle from its point of origin to the dealer. It costs roughly the same to get the 328 to the dealership as the Volvo.
With respect to fuel economy, the Volvo C30 has the BMW 328 beat.
As far as MSRP, the BMW 328 costs considerably more than the C30.
Handling
With their similar turning radii, the Volvo C30 and the BMW 328 most certainly handle almost the same into and out of tight spots.
Drivetrain
The BMW 328's engine is considerably larger than the Volvo C30's. Keep in mind that more massive engines may use more gasoline than smaller ones.
Torque equals pickup, and the Volvo C30 will have picked up and gone by the time the BMW 328 finally gets moving.
The BMW 328 could learn a lesson or two from the Volvo as far as pickup.
Comfort
While the front cabin in the C30 offers a bit more head room than the BMW, there really isn't much of a difference.
While the rear of the Volvo C30 offers a bit more head- and leg-room than the BMW 328, there frankly isn't much of a difference.
Warranty
The Volvo C30 and the BMW have the same basic after-sale protection.