A4 2003 v6 will not select gears. it goes into D and R but when i drive it will not go to next gear

SOURCE: Reverse gear problem

Change the Transmission filter and flush the fluid in it, I'd be willing to be the factory filter is still in these trannys and it's about clogged up, gettin worse once the fluid heats up. The pump won't build enough pressure to allow it to act properly.

SOURCE: Audi won't shift out of first gear

check your inhibitors switch or the shifting cable.

SOURCE: VW GOLF 1.4 1999 S. Gearbox makes whining sound at idle

No good news on this one I think
Your whining sound problem is the Layshaft bearings in the gearbox are badly worn. It also seems that the baulk rings are damaged on 5th gear.
John

SOURCE: Ford Escape Automatic Only Goes Into 1st Gear Manually

it sound like you have a vacum leak or your shifter cable may need adjusted

SOURCE: Prob's with my Audi A6 2003 Auto 3.0 V6 (gearbox)

Doubt it as the fault suggests you need to look into the range sensor. If similar to Renault there is a switch on the gearbox that senses where the select lever is (at the gearbox end). If the display is wrong then the sensor needs looking at and either it will need to be adjusted into a set position by moving it, or perhaps the connector to it or wiring to/from it have a fault.