There was nothing wrong with the AU except some poor decisions regarding its conception and marketing - it was a good car, but simply not what most people wanted. Its interior was cheap and if anything had less showroom appeal than the EL it replaced. But it made a great taxi.
I wouldn't necessarily look for a Classic model as they are rare - to be honest I haven't heard of them, only the SR.
The AU II is a better car if you can afford it with improved front crash safety, reduced noise levels, added features such as better brakes, slightly restyled dash, 16" wheels on all models, sunglasses holder, etc.
If you want cruise control and ABS standard, the Futura is the pick of the range. A CD player was fitted to all models from the AU II and onwards. An AU II Futura can be had for the low 20s, or maybe even less.
Performance is impressive on all models. An original AU Forte will accelerate 0-100 in 9.0 seconds, and weighed less than its predecessor so used less fuel. LPG versions have running costs on par with a 1.3 litre four cylinder car according to RACV tests.
Jack Travis, E-Series Acting President
1989 Ford Fairmont Ghia turbo/GL replica (underway)
1994 Eunos 800M
1990 Ford Laser S