A testdrive is no indication whatsoever of future reliability. From a testdrive you may be able to assess the cars appearance, interior feel, quality and ergonomics. You may be able to tell how the engine sounds, and get a vague idea of the steering (Is it sharp, or is it like a Camry).
I seriously doubt you can get much more from it than that. Probably most importantly you will get an idea of the customer care and service of the dealership.
In the modern age, even auto gearboxes can't really be tested in a test drive. Some drivers will get in and thrash it, others will baby it. So its computer will be confused, and act like a confused person would - like an idiot.
I guess some preliminary research should reveal that the C4 shares its autobox with various other PSA cars. Therefore it should probably have been known in advance that its an 'aquired taste' (or, to everyone else, confused, idiotic).
Its very disappointing to hear about interior quality, but after veiwing the C2 and C3 (Chux wipe roof material anyone?), can't say I'm surprised.
C4? Well, at least its individual. The Astra is an awesome car to drive, but its an Astra (an issue for some). And the Golf? To paraphrase jeremy clarkson, 'they started and finished with a blank peice of paper'. The C4 has many things going for it, but it certainly is'nt THE ANSWER for everyone.
Never nice hearing buyers remorse though
