MERCEDES-BENZ has given its SLK convertible a mid-life freshen up. The changes are not massive, but two engines have been upgraded, the styling has been given a nip and tuck and there is a new steering system. Upgrades to the supercharged 1.8-litre four-cylinder have boosted power to 135kW, while the revised 3.5-litre V6 now belts out an impressive 224kW without using any form of boosting. Mercedes is also placing an emphasis on manuals, making the gearboxes standard fit on the SLK 200 and SLK 350, rather than leaving it as a delete option.