Amri
Been using a power washer on mine for 4 years! As the guys say, just don't get too close with it. It helped strip off my old alloys

I have a brush attachment which forces the washer to use a lower pressure. I use that with the foam.. Maybe the same with your foam attachment?
Rinse off with power at a distance and never on the soft top. Autoglym is your only man. Been using it since I had the car and my vinyl roof is still in good nick. Specially before the hard top goes on.
Get some alloy cleaner/ protector too. Having wax on the rims really helps when washing the brake dust among dust in other areas off after scary sliding!
Drive safe. And we will def have to meet up as I'm in Dublin too!
Shenab