Scirocco Register

So I bought some BBS RZs with tyres for the Scirocco today and it's all gone a bit slippy. Almost dangerously so. Some info:

Tyres have tonnes of tread (the ones I took off were on advisories).
Suspension setup hasn't changed. Wheels appear to sit fine on the ground (not on either edge etc).
Less grip on new wheels/tyres in both wet and dry. Thought it may have been the wet weather, but my other car was fine.
Tyres all at 28psi as they were checked before putting them onto the car.
Tyres are Mentor M300s. Never heard of them, but they don't appear aged/cracked/old etc. Rubber felt soft, but I'm no expert. Will check the date though.
When stood still, the steering wheel is lighter than before.
It's currently sliding more at the front, although I dare not test the rear.

I had been tinkering with the idea of semi-slick tyres at some point (R888R specifically), as I rarely drive in the wet, but that was a "nice to have" rather than a solid plan, but if it turns out my current tyres are crap, I may have to upgrade that to "oh go on then"!

The offset of the wheels will affect how light the steering feels, but basically you need better tyres.

They are probably harder compound, but you can also check the date on the sidewall to see how old they are. Google it if you're not sure what you're looking for.

this may sound daft but when i first had some nankangs on mine they were dangerously slippy so i went into a quiet carpark to give them some stick as i thought i was going to bin them anyway and they very quickly got a lot better. it was allmost like they had been coated in something, so once it wore off they gripped brilliantly.
at least its the free option before you have to spend any cash

I meant to update this. It does indeed seem to be getting better with use. I dropped the psi to 26 as recommended by the sticker in the door area and drove the car for a bit, maybe with a bit of wheelspin for good measure and it seems to be at least drivable now.

I still plan to get some decent tyres at some point. But these will do for now.