Advice needed on removing interior door panel

[JakeS77]

I need to remove the driver's side door panel on my SLK R171 2007 to access the window control unit as it's only operating intermittently. I've removed all the bolts bar one which is well hiddden.

Under the armrest there is a very small flap cut into the door panel and I can feel a screw in there but am not able to see it. I assumed it would be a Torx or if not a Philips threaded screw. But I can't get screwdrivers for either of these types of bolt to marry into the screw head. So I can't undo it and this is all that's stopping me get the door off.

Does anyone have any ideas on how to undo it without taking it to a mechanic? The other door bolts are Torx size 15 but this bolt doesn't seem to be the same.

 

[JakeS77]

 

[bembo449]

so whats the issue , is the driver your using not long enough or too fat to access the hole easily ??

 

[AnthonyUK]

I bought a set on long torx bits for under £10 which have been perfect for removing door trims and head unit/trim bolts behind the air vents.
The door bolts should all be the same size.

 

[JakeS77]

so whats the issue , is the driver your using not long enough or too fat to access the hole easily ??

I've got T10, T15 and T20 long screwdrivers which all fit into the hole but none of them will latch onto the screw head. All the other bolts on the door were fine to remove with the T15 screwdriver

 

[mattkh]

I've got T10, T15 and T20 long screwdrivers which all fit into the hole but none of them will latch onto the screw head. All the other bolts on the door were fine to remove with the T15 screwdriver

Any chance of a close up picture or
a description of the head of this screw.