ok guys here they are. 1,transponders are different. 2,need to wire dbw or not. 3,need to rewire dials. ok the plan was to put a 1.9 tdi 110 from a 1999 a4 avant into my 1.8 adr 1997 a4 avant. engine,fuel tank,lines,plumbing and everything is done other than whats above. now starting at no 1 the transponder(if thats what its called) on the back of the ignition barrel is different, 1997 has a long tapered bit that slots into the back of the barrel,1999 has a thin tapered part that does not reach the innards of the 1997 barrel. do i need to change the actual barrel cylinder too. no2 1997 had a cable throttle,1999 has dbw throttle.is my 1997 pre wired for dbw whereass they have hidden the plug.or do i have too wire this in. no3 the two plugs on the back of each dials are different to each other is this a matter of popping the pins and relocating to facelift plugs or is there more too it. any help atall guys and girls is much appreciated. also another downer to my day was that i found a hidden 1.9 tdi quattro sport 1997 that has been laying for a year and a half and the guy would not sell it.i was so so sad.lol.