The magic safe place has struck again. I took the indicator / Side light covers off as they needed a complete strip and clean. I put the 10 screws in a safe place. I now can't find them...
lol Yes we've all done that more than once I'm sure!
I presume the are Phillips raised countersunk size 8 * 25
I haven't got one to hand but I'll see if I can take one off mine later today, but they were definitely not countersunk.
They are a Philips panhead screw with a self-tapping type thread, that cut into the composite bumper, although some had a speed clip at the back into which the screws could grip firmly. Now if they have been in and out many times, or overtightened, that can damage the 'thread' in the bumper such that the screws no longer tighten securely, especially if there are no speed clips. If the holes are like that then you could fill them with some new resin (and maybe a little matting) first and let that cure, before drilling a small hole in the middle for the screw to start and then make a new cut.
Update: They appear to be panhead self-tapping screws approx. 20mm, possibly 25mm long, and approx. 4mm diameter or size 8 (which is 4.2mm). They could be a straight screw driver slot or Philips cross type, doesn't really matter.
Roy