Hi Dan,
the break pad warning light is just the break wear sensors not been fitted back in and I never got around to doing it,
the exhauxt took a knock when reversing out of a steep driveway, bit blowy but again never looked into where from,
the steering started making a noise on the drive back from the dealers after signing for the new car...just topped it up asuming it was just low (never checked it since owning it)
as for the LPG, when trading it in they were aware that it was not in working order, the bayonet filler wouldnt accept the pump attatchment and would vent LPG without filling,
I never got it fixed as the LPGs ECU never agreed with the cars ECU as I used to chop & change between fuels, with all the sensors on the car I think it just plays havoc with them.
(it`s quite an old LPG conversion and not many garages were willing to look into it, so it just got left)
on a plus side, the chain jumped and its had a top end re-build, including new chain kit, valves & guides.
sorry that your not happy with it, but I had to get rid of it and was as reasonably honest with the garage as possible, they were fully aware that the LPG wasnt in full working order.... more than I was when I purchased the car!!!
I got a freinds & family discount off the new car of £1500, as they only really gave me £500 for the Vectra,
Hope this helps.