please. so are u saying that the audi and vw;
a) not stable,
b) dun have "high" power steering, and
c) dun have "strong" ext. body?
it is obvious that the threadstarter wanted a comparison between
the 3 performance based models, to be specific, the alfa 147 GTA,
audi A3 sportback quattro and VW golf R32 4motion. giving biased
opinions based on keen knowledge of one particular brand u are
familiar with obviously shouldn't be the objective of ur post.

btw, big fuel tank is no advantage IMO when u are talking bout
modding car. more fuel = more weight = slower car. 
me personally think either the VW or Audi makes a better driving
platform, AWD versus FWD of the GTA. engines also pack more
potential for power being force inducted in comparison with the
GTA's NA characteristics. not ragging on the GTA entirely though, i
do have the impression that the GTA would be more fun to be driven
and more reliable in the long run.