Polk Audio Mm12g 12" Mobile Monitor Series Subwoofer/sub Woofer Grille/grill on 2040-parts.com

Spied on the street: Porsche Panamera

Yes, Porsche has given up several official photos of the Panamera sedan ahead of the car's expected official rollout at the Shanghai auto show in late April. That means prototypes on the road have stripped off the camouflage. But it's still interesting to see the car in a natural setting.

BMW Z4 (2013) new engine and facelift

This is (really) the new BMW Z4 for 2013. Granted, the tweaked head- and tail-lights, and new side vent modelled on the BMW 4-series are subtle alterations at best. It's what's under the bonnet is of more interest, if you've always fancied one of BMW's folding hard-top sports cars on your driveway.

One Lap of the Web: The Economist talks cars, Maria Sharapova's Porsche and crazy bikers

We spend a lot of time on the Internet -- pretty much whenever we're not driving, writing about or working on cars. Since there's more out there than we'd ever be able to cover, here's our daily digest of car stuff on the Web you may not otherwise have heard about. -- Have you ever seen two motorcycles going wheel-to-wheel at 200 mph in the rain?