My Audi has cruise.
There's a button on the end of the stalk to set, up to increase speed, down to slow, push away slightly to disengage, pull back to reengage, away fully to switch off. It's soooo much better than the GT.
The button on my fob won't release the boot on the GT without setting the alarm off so I have to unlock the whole car and use the button on the boot. The inside button works. There was a thread which explained how to set it from the menu in the car but that didn't work!
The wipers are a bit of mystery. As far as I can tell (and it's not clear from the manual) is that all the way down is the least sensitive setting. You also need to remember to turn them off and on again otherwise they don't work automatically.