Mercedes-Benz SLK350 Roadster. The SLK350 has a 302-hp 3.5-liter V-6 engine and combines numerous advances to deliver more torque. Shaped by a rich racing heritage and the wind through which it slices, the SLK wraps purebred performance in perfectly proportioned muscle. From its crossblade grille to its signature power hardtop, its passion is expressed openly. LED lighting adds scintillating style to the inner strength that its aluminum-trimmed roll bars assert.