Defender 90 300tdi '97 heater box

Hi all
Some advice please re the Heater box on LHS of bulkhead.
I wish to fit a reversing sensor control box onto the heater box with a couple of self tappers. Is it OK to drill through the front face where the LandRover sticker is?
As I am a one eyed Landrover Driver I need sensors on the front so that my nice hard steel bumper + tow hitch dosn't do some damage to the car/wall/garage door in front!
Is the heater matrix at the back of the box with the front just being a plenum chamber?
Look forward to some good avice before I bite the bullet and drill two 5mm holes!!!
Cheers
Jerry
Nr Bath
UK

Yep, go for it. The heater matrix is towards the back of the box. I have an extra washer bottle screwed on that spot, no problems.

Thanks very much for the info - It's out with the drill tomorrow!!!
Cheers
Jerry