If your Stag has air conditioning.

if the Stag has A/C there is even less room there and that speaker really doesn’t fit.. OK some of us crammed it in there but it’s not easy, and mine does not line up with the cutout. In the end I could not work it in without partly removing the dash, I was re assembling the car so had lots of access, I would have given up if the car was fully assembled.