ive got exactly same issue as you had u reckon could be same as can this wire be accessed without removing things?
I just had the same problem. Tried to start my 1998 1.6 Scenic just after parking and the starter solenoid did not operate at all (no clicks)
Tried it again about an hour later and it worked ok.
I have followed the advice of gdburton and checked the solenoid trigger wire connection.
Ideally it requires access from underneath the car but I dont have any ramps.
I managed to get at the connector from under the bonnet by reaching round the back of the engine.
(I could just about see the connector using a mirror and torch.)
After pulling off the connector, I tried to clean the solenoid contact with some abrasive paper and I could just about manage to reach the connector to spray it with some contact cleaner. The wire did not reach far enough for me to replace the connector though.
I don't yet know if this will cure it though.
I also looked at the earth wire connection to the gearbox which was nearby (using the mirror) it looked ok and the earth wire felt like it was firmly bolted there.
Accessing the solenoid trigger wire from under the bonnet was quite fiddly and there were some sharp edges to scrape your arm on, so I don't recommend it unless you have to.