You're correct about the tyres in part ,
They are new tyres but are crap! A mate recommended Toyos, they are the worst Tyre of any car i've ever had. I fill them to 26/27 psi just to stop them screeching when cornering & pulling away .Initially I thought they would bed in - no such luck. I suspect they may well be fine on a conventional car, but with only 22 psi & a very light car , they just don't have wall stiffness/rigidity to cope!
The first job next spring is to change them .
Any recommendations are welcome
Strange I just removed a set of Michelin tires because the wall was too stiff. Not compliant. However I did like them in the rain. My new tires have a softer wall but noticed that in the rain they were not as good as the Michelins. Damn if You do Damn if You don't!