You need to pull the head unit out of the dashboard, then connect the wires.
there is one there, I slways start from the frontwhen doing installs. Take the head unit out and run my RCAS and my remote cable from the head unit hole and work my way back.
However, my new unit has a processor box in the boot, so easy to wire
ive put stereo systems into literally a hundred cars, And I Can confirm that a clio mk 2 is one of the easiest.
Have you got your power wire through the bulkhead yet?
The hole i used when i did my mk 2 phase 1 was down by the glovebox, Cable tied it under teh glove box and came up the passenger side of the car.
Push a wire through the hole that the headunit came out of and see where it ends up....
Try and divert the wire towards the drivers footwell as i assume thats where your puttin the wires?? Watch they're not in the way of the pedals though
I assume the power cable is down the passenger side??