Under the hood of this 3rd generation convertible, Carlsson has developed a new C-Tronic kit with different stages of output boosts for the new range of CGI engines found in the SLK. For the SLK 200 CGI with a standard output of 184 PS, the C-Tronic tuning can dial the horsepower to a maximum of 224 PS. There's also a less powerful boost up to 211 PS. For the higher end SLK 250 CGI, power gets bumped up to a maximum of 239 PS from the original 204 PS.
The interior of the SLK receives an upgrade from Carlsson’s own upholsterers based at Gut Wiesenhof. These experienced master upholsterers have come up with a combination of colours and materials for the SLK, which can be personalised with matching beading and stitching upon customer’s request. Carlsson Nappa, Carlsson Nappa Exclusive and Carlsson Nappa Exclusive Heavy Weight are offered as part of a basic package consisting of the upholstering of the two seats, the headrests and the insides of the doors. The interior is further refined by the use of pedal pads made of brushed aluminium with Carlsson logos. The Carlsson gear stick has a choice of trimmings that include Alcantara appliqués, individual carbon features or fine wood inlays.