I have a 2006 Civic 2.2 ctdi Sport(71k miles)and Mrs fivespot has a 2005 A3 Tdi 1.9 (111k miles). I have only had the Civic about 9 mths, no faults or problems in that time, but the clutch has always been a bit juddery (suspect a DMF issue) but has never got any worse. £120 PA road tax not £100, economy has not been what I was hoping for, low 40’s knocking about, 50 on motorway. Great on SMOOTH fast A roads, but crap over anything with a hint of roughness. On the plus side, the seats are very comfy and supportive. It doesn’t pull from as low down as most diesels (around 2000 RPM for proper boost as opposed to about 1400/1500 for other diesels I have owned/driven) this has been improved no end by a black box from ebay, as well as more MPG. Big boot, partly because of no spare wheel, and partly down to clever rear seat pivot design when folding down. Not Audi build quality, but not bad either. My 1st Jap car in over 35 years of driving, mainly because my last car (2006 VW Passat) had more electrical problems than the previous 50 cars I have owned put together. If the ride and clutch were a bit more refined, then I would be very pleased with it.
Onto the A3. We have had this about 2 1/2 years at least, apart from normal servicing and tyres, it has needed nothing. In the last 3 moths it has had a random showing of a warning light on the dash, starting, performance and economy are unchanged. Although the mileage is 40k more than the Civic, it drives smoother and with a more solid feel, uses no oil or other fluids. It is a base model will few extras (no on board computer) but seems to go further on £20 worth of fuel than the Civic. I think a higher spec version with a bit more poke would be a lot more fun, but for what Mrs fivespot wants, its been perfect.
Mrs fivespots opinion is slightly different. She loves her A3 and thinks the Civic is a girly car (but what does she know)
As far as Golfs/Jettas of that year, I can’t comment on the years you are looking at. BUT of the two VW’s I have owned:-
2002 Golf 1.6 petrol…the dullest car we have ever owned ( and I have owned 2 Allegro’s ) like driving a water bed with a whining gearbox (only 62k miles) and then the exhaust fell off. Got rid of that for 2002 Focus 1.6 petrol, WOW, great handling and better ride quality. Kept it nearly 3 years (a long time for us) only parts replaced appart from service items were front drop links (cheap easy home job)
2006 Passat 2.0 Tdi essate (about 110k mile) Tailgate kept opening itself, doors wouldn’t open, used oil, multiple suspension knocks, the dash had more warning lights than I can remember.
Hope this helps a bit in your choice.
P.S. Try a Focus 1.6 TDCI, cheaper, low tax, great ride/handling