Firstly the instructions, which are less than useless and at some point just misleading. Then there are several components which simply don't fit. For example, there is a supporting bracket which fits under the front of the pop top which doesn't fit the the roof line of the van. You will end up using clamps and rivets to pull the shape of the van down by about an inch to meet the bracket. This feels like its making a 'well' in the roof of the cab which will collect water. Very wierd. There are two 'L' shaped plates either side of this bracket which don't line up with anything at all, and you will end up bending them and cutting bits off to try and get them to line up with anything at all. Oh and the right hand bracket should bolt to the grab handle mounting point above the driver's seat. Which doesn't exist. The rear support bracket doesn't line up with anything structural at all, I think its the skin of the roof which holds everything in place which can't be right. Again, the beam doesn't meet the roof properly. The biggest and most scary part of the job, cutting out the roof, the guidance is pretty much non-existant, you'll end up guessing where to cut, which is just worrying. The instructions have no reference to a datum line on the van! You have a basic outline, with reference to each corner, but there is no measurement front to back in reference to the windscreen/ rear door. I rang the workshop and they just laughed and said 'yeah its rubbish isn't it'
The main bracket hinge should in theory be simple as it picks up an existing hole, but the holes are not obvious. I'd suggest dismantling the bracket and marking the holes directly from it onto the roof. There is a line down the gutter on the roof which looks like it should be the centreline for the holes. It is not. Swearing and shouting follows. The instructions specifically says 'don't overtighten' the rivnuts, which is a strange instruction, because if you don't tighten them enough, the rivnut spins before the bolt is tightened down and then cannot be removed or tightened. Then lots of swearing happens.
The pop top itself is fine, its the structure and support underneath it which is absolute garbage.
As for customer service, They were a month late on delivery, there were several fittings missing, which they denied and I just had to go any buy my own, the bed deck was missing, which they then denied I ordered and made me pay for again seperately. They said there would be be support over the phone if I got into difficulties, I rang once when i first started seeing the issues, then they immediately (within half an hour) closed for a long weekend when I was fitting it.
If you do fit it yourself, i'll help out as best I can, I think I've found all the issues and next time would be easier, it is cheap after all!