Hi, as usual the Nazis with no real idea of how to implement these things reply first.
Remote start can be fitted, however depending on what phase your Clio is depends on how easy it is to do.
I have a Clifford inteliguard alarm, it has the remote start feature, but on a phase 2, to bypass the immobiliser properly you need a breakout chip, which sits from the immobiliser to the obd port. It means that if you need the obd function on your car, its hard to get at. These breakout chips are around £150.
If however you have a phase 1, the immobiliser can be bypassed much more easily, with no cost.
It is possible to get around the immobiliser another way, which I know a lot of people do, you may have seen it yourself but this is why there are insurance implications.
If you can fit an alarm, you can easily add remote start. It's 6 wires or so, requires a little diagnosis of cables and you're away.
If you need help wiring one, pm me and I'll give you a hand.
The other insurance implication is that your car won't be covered as if you remote start it in gear and it jumps its way into something its downright dangerous, that's why these should really only be fitted to auto boxes.