The towbar has definately hit the road a few times as you can see where the paint has scraped off it. Theres 4" of clearance at the lowest point and it only seems to contact on steep slopes or if i straddle one of those square speed humps.
Its a Peko one made from 4mm angle so i'm more likely to damage the road than it.
Can't see anywhere else that its hit.
I might still remove the mudflaps before i use it next to rule them out as the cause of the bang.
The Z bar rubbers are in contact with the cups that are mounted on the axle tube as its slightly lowered at the back but i forgot to look at the bump stops to see how much clearance they have.
I removed the seat and trimmed the section on the back of the seat base.
It used to be like this (arrowed) all the way along and the back 2" hung off the back of the floor mounted rails and hit the floorpan when the seat was all the way back so I trimmed it down like the area circled on this piccy.
The seat now slides further back and i have gained 1 1/4" (32mm ) of leg room. The seat can't go back any further and lock into place unless i trimmed the curved tubular section of the base and cut off and rewelded the locking teeth further back.