I have just been having another look at the German Pricing and Specification Guide for the 8V and it contains the following item:
Dynamic suspension
Forward with a McPherson strut axle with lower wishbones, aluminium subframe and tubular stabilizer.
Back with a 4-link rear axle with separate spring-shock absorber arrangement, subframe and tubular stabilizer.
For the 1.2 TFSI 77 kW (105 PS) and 1.6 TDI 77 kW (105 PS) a slight twist-beam (torsion bar in English) rear axle is installed.
So that seems to confirm the situation. The two 77kW (105 PS) engined models have the 'torsion bar' rear suspension and all the other engine sizes have the '4-link rear axle'.
It's a shame Audi UK don't include this information in their Pricing and Specification Guide as well then there would be far less confusion.
Dynamic suspension
Forward with a McPherson strut axle with lower wishbones, aluminium subframe and tubular stabilizer.
Back with a 4-link rear axle with separate spring-shock absorber arrangement, subframe and tubular stabilizer.
For the 1.2 TFSI 77 kW (105 PS) and 1.6 TDI 77 kW (105 PS) a slight twist-beam (torsion bar in English) rear axle is installed.
So that seems to confirm the situation. The two 77kW (105 PS) engined models have the 'torsion bar' rear suspension and all the other engine sizes have the '4-link rear axle'.
It's a shame Audi UK don't include this information in their Pricing and Specification Guide as well then there would be far less confusion.