Ive got 2 Corsa 1.2's, ones a a Van and the other a 3 Door Car, both are Dual Fuel LPG and save me an absolute fortune in Fuel Money.
I would highly recommend them for little cheap run arounds , ok there not the fastest things on the planet but do a good job of MPG, wack them in 5th at 25mph upwards and they will save you fuel.
Plodding in and out of London I get around 37mpg on LPG, thats about the same as around 44 MPG on Petrol litre for litre, but cost wise at 55p a litre for LPG works out the same as buying Petrol or Diesel and getting around 90 mpg (6.5p a Mile). On a Motorway or good run I can squeeze about another 30% out on MPG.
the 1.2 is the one to go for, forget the 1L which is a 3 Pot theres just not enough torque and your end up potentially doing more fuel.
Chain rattle on Start up is fairly normal for a 60K Plus Corsa and nothing to worry about, as for the rest there a cheap fix to keep on the Road.