Possible mounting points formrelay and fuse box

[SonOf]

Hi guys,

Finally getting some time to work on my car so have started to install new wiring harness for headlights and tidy up the exisitng spot light wiringmand add a light bar. I am re-running all the wires and will be running the spots/barm off the auxilery battery.

Most of the space for mounting on the side is taken up by either the battery or air box so wonering about mountingmthe relays and fuse box to the back P/side fire wall and wanting to know if the 4 screws in the attached pic can be used without any issue, also any idea what they are for?

Car is a 99 GU TD42 Wagon.

20160407_093157.jpg

Cheers guys
Shane