Behaviour of the automatic transmission at high speed

Hello, I drove a 98 a8 4.2 quattro test today!

the car is overall top in shot, the automatic switches gently and without any problems! One thing seemed strange to me, though:

I did a kickdown on the highway at about 140 and accelerated to 180. when I am then of the gas has the automatic but not me
immediately switched on again but remained in the same gear and has practically braked with the engine. with the tiptronic you could manually immediately switch up again.

I know it from automats actually so that as soon as I go after a kickdown of the gas, it switches right back! the salesman said that the automatic system would be noticed if you gas at high speeds often and kickdowns and then do not switch again with intention. so to speak intelligent sports automatic.

So my question: is this a normal behavior for automatics?

one more question: the steering has cracked partly at steering maneuvers, sounded like when the blinker jumps out again after the turning process! What can that be?

for answers already many thanks in advance

==References==