Neil-yaj396 that gray plug is for the rocker switches under the radio - i believe its for the electric aerial, opposite end can be found in the boot, so just pop it behind one of the blanking plugs where it should be.
Can't remember if the black plug goes behind the speedometer (been a long time and my memory is going) but you will know if its wrong as the instrument panel wont work properly, fuel, temp, petrol gauge, main beam lights etc read wrong or don’t work - all you have to do is pop the ignition on to check before you continue as it wont do any damage.
Best way to remove an instrument panel is to push the speedo cable through from under the bonnet as far as it will go (even if you have to undo p clips) to give you enough slack to unclip it, then you unplug the wires and the oil pipe.
To refit the instruments plug in the wires first (check they work correctly first by turning the ignition as mentioned before) as the two large ones will fit in either slot!
Once satisfied they are working right connect the speedo cable and lock it properly by sliding the sleeve forward (you will find out why its important in a minute) connect the dipstick pipe and the trick to get it all back in is to pull the speedo cable as the instruments are pushed back until they are fully home - if the speedometer cable is not locked it just pops off.
If you don’t the instruments just keep springing back out and if you do manage to force them in the speedometer can actually become offset within the cluster - you can actually see this!..... then you get the clicking or the "flicking" speedometer needle as you drive.
Incidentally should you realize when it is too late the dipstick pipe has come off it can be reached from below the dash to save you taking the cluster out again.
capriblu some after market speedometer cables are not very good and have too much flexibility where they connect behind the panel and this can lead again to the "flickin/clicking" problem, Neils looks original?
Once satisfied its all back in as it should be go tend to the inevitable cuts and grazes on your poor hands.