On manual cars you can try greasing the gear selector, there's a guide in the appropriate section i believe.
Only AMT's have clutch actuators, that do the job of our clutch slave cylinders by depressing the release bearing fork with an electric motor and worm gear instead of a hydraulic piston like on manuals.
Grinding when shifting in reverse is a common forfour QUIRK, not quite a fault unless it always does it, even when stationary, and you'd also feel it snag when trying to engage first gear, and also getting out of first or reverse will be difficult... Then it becomes a problem, and the clutch kit needs changing,because the release bearing or pressure plate aren't up to the job of completely disengaging the clutch anymore.
To avoid grinding when selecting reverse, ALWAYS make sure your car has come to a complete stop, depress the clutch pedal, shift to neutral, release and depress the clutch again and only then shift into reverse.
If you feel it hasn't got all the way in, very slowly release the clutch, this will pull the gear lever into reverse and you can move away without any grinding or jolts in the transmission.
Double depressing the clutch prevents most of the grinding, as does waiting a second or two before reversing directions or i sometimes go 1-2-R if I've got a lazy leg...
When checking and cleaning the throttle valve also look at the MAP sensor, it's cleanliness is even more important. Don't expect dirt or cooked up oil on them either, a thin film of burnt oil is all that's needed to coat them, harden and form a small lip around the butterfly valve and affect running.
