U will need adaptors to convert the hub to suit merc, or porsche wheels. The tool you speak of will be used to wind the 2 ring nuts up or down to adjst your ride height. You can simply use a tape measure on the visible thread to get an even height all round. What wheels / tyres are on the car currently?? Check the tyre and inner arches to make sure they are not rubbing.. (most tyres over 205 will run without having your arches rolled)