Volvo 940 Guard alarm LED indicator

I your 940 is not fitted with a Volvo guard alarm, you do not have the LED indicator in the front left speaker grill.
If you want such an indicator, you can use this design.

The speaker grill shows exactly where to carefully cut (dremel tool) the rectangular hole on the backside. 

Part B is optional. You can glue it on the back side for a slightly better mounting surface.
I hot glued it in place.
The part is made for a 3mm LED, just drill the hole to 3mm and the LED will fit tightly.

Note that the finish on my printed part shown is not optimal. I printed it at 0.3mm layer height. Cleaner results are to be expected with 0.2mm or 0.15mm 

Note:
Due to potential high car interior temperatures in summer time, do not print in PLA! (it will melt/deform)
Print in ABS, ASA or other more temperature resistant material