Ok... Update ! For once, the weather was shiny yesterday, and I wanted to swap my wheels... I started by the rear ones, without any problem, even though there is less than 2 cm between the exhaust line and the tyre (but I assume it's not a problem, right ?)
But things are different for the front [
]... As a member already told me, the steering arm is fouling with the inner rim, and wheel can't even turn (see pic) ! I thought that the Hawk/compomotive was made for the MKIV, and this was a part of my decision vs the Trigo...
So, I had to put the 16" wheels back, and now need to find a solution : either bending the steering arm to clear the rim (geo needed and maybe more weakness) or having a spacer made (but will the pegs be long enough) ... 4 or 5mm should suffice.
For those who have choosen the Hawk wheels: did you encounter the same issue, and what was the option choosen ?
It's a pity, because it does look good withe the 15", and a quick test with the rear ones fitted showed a very good grip ...