Ford Focus have roof rack fix points

Whilst looking for a set of rook racks for my 2005 Ford Focus, I discovered that there are 2 types of roof racks available, those for mounting to a set of "fixpoints" and those that can be mounted without the Fix points. The roof bars that don't require the fix points clamp onto the roof and into the door opening and due to the limited clearance available between the door and it's frame, the clamp seems to be painted metal with no protection for the paintwork. I'm not overly happy with the idea of clamping painted metal against painted metal, especially when it's going to be subjected forces and vibrations that you could expect when driving the car, this is therefore an option I'd rather avoid. Those with fix points have a bolts that are attached to 4 tapped holes in the roof on the car. In the case of the Focus there are 4 plastic panels that can be removed from the top of the car to access the fix points, only at first glance you may well come to the conclusion that your car isn't fitted with them. This is the conclusion I almost came to, but luckily I found I was wrong.

The covers on the top of the Focus are easy to remove, there is a locking mechanism at one end, a quarter turn will unlock the cover. The slot provided is fairly wide and curved, it may be possible to use a finger nail or screw driver, but I found that the shape lent it's self to the use of a 2p coin as a key.
Fix Point Cover
Once removed, there is no obvious sign of a hole. I had found websites which said that the hole was covered over prior to painting, but I was expecting to see a circular indent or something to suggest that there was a mounting point present. A bit of a prod with a screwdriver lead me to the discovery that what looked like a part of the metal chassis was in fact sealant of some description. You may be able to make out a small cross-head screwdriver impression in the sealant in the picture below.
Cover Removed
Using a small flat head screwdriver I was able to cut a small circular portion of the sealant out, to discover a small plug with a cross type screw head. The sealant is about 5mm thick above the plug, the plug being about 6.5cm from the front of the recess in the roof.
Plug Revealed
This plug seems to be pushed into the screw thread. Once unscrewed and with a bit of leverage to lift it out of the hole in the sealant, a screw thread is revealed.
Plug Removed