our Cali doesn't currently suffer from a sagging rear end but we haven't every fully loaded it. From our previous spring investigations we a level 4 spring but I came across this pedders kit and thought I'd canvas opinions on it's suitability.
http://www.pedders.co.uk/pedders-su...ear-suspension-kit_p22541206.htm#.WLZ2lZHfWhC

http://www.pedders.co.uk/pedders-su...ear-suspension-kit_p22541206.htm#.WLZ2lZHfWhC
