The Aero range has the same width wheels all round but a narrower tyre on the front. This means that the alloygators do not fit properly as the tyre is stretched out a bit on the wheel
So that is why the Alloygators didn't fit!
I'd naievely assumed that the front wheels were narrower than the wheels, not just the tyres.
My immediate thought is what would be the effect of fitting slightly wider front tyres, so 235 rather than the 225 OEM? Avon has discontinued the 225 with tyre with the ZZ5, but the 235 is offered.