relative to the rear tunnel 108 the front suspension arms 154 in this embodiment are made of tubular metal and the attachment thereof to the tube 156 are preferably reinforced by triangular plates 162 see fig7 which are preferably welded to both the tube 156 and the front suspension arms 154 a rear suspension arm 164 which is preferably made of a hollow metal configuration having a substantially consistent rectangular cross section is downwardly and rearwardly angled and is disposed behind the front suspension arms 154 the rear suspension arm 164 is pivotally attached to the rear tunnel 108 of the chassis 106 by means of a tube and shaft assembly not indicated the tube and shaft assembly includes a tube 166 rotatably supported by a shaft 168 which is substantially parallel to the shaft 158 and is mounted at the opposed ends thereof to the rear tunnel 108 the upper end of the rear suspension arm 164 is affixed by for example welding to the tube 166 so that the rear suspension arm 164 is adapted to pivot about the shaft 168 the lower end of the rear suspension arm 164 is pivotally connected to a pair of rear rocker arms 174 by means of a hollow cross bar 172 the rear rocker arms 174 flank the rear suspension arm 164 and are in turn pivotally attached to a rear portion of the respective slide rails 146 a.