My first thought is that you should be coasting in gear. If in gear, fuel supply will be cut off whereas if you are in neutral, fuel will have to be supplied to keep the engine turning. As to the rpm, no idea. What other controls are you using, e.g. brake?

I have recently had the cam belt / water pump / tensioners replaced on my Sharan.

I've noticed something which I'm fairly sure didn't happen before but it may be I just hadn't noticed it.

If the car is on a slope and I coast in neutral with the clutch out from stationary to about 5 or 10mph the rev counter creeps up - if i then slow to a stop it goes back down. - ie it is changing in direct relation to the speed of the car. Beyond about 10mph there is no further increase in revs. A/C is off.

Any thoughts?

Only a couple of thoughts really, one, its gearbox oil drag causing the engine to raise revs, or the ecu raising the revs because the speedo sensor is out of sync with the engine, so compensating....but I could be wrong?

If the car is on a slope and I coast in neutral with the clutch out from stationary to about 5 or 10mph the rev counter creeps up - if i then slow to a stop it goes back down. - ie it is changing in direct relation to the speed of the car. Beyond about 10mph there is no further increase in revs. A/C is off.

Any thoughts?

It's normal.

I've certainly noticed on a vehicle I used to drive (2003 Renault Master) that if you moved off from a standstill (in neutral downhill) that the revs would raise slightly (probably by 200RPM). The revs would drop back down to a normal idle speed if you went above about 10mph. The revs also dropped if you stopped.

I always assumed it raised the revs slightly to reduce the risk of stalling when setting off.

If setting off in gear, it drove fine.

Think I've had other vehicles which have behaved in a similar manner.