This car has a blown diffusser...
yup. That may explain their rear end grip. It's very suttle and passive, but the diffuser similar to the double diffuser days ia blown by free stream air. The difference is that the air comes from the outer flow to the side pod and is rammed in by a turning vain behind the wishbones. This air turns in toward the centre of the car and contacts that blocker under the crash structure. It also is accelerated throught the starter hole. this is a neat littlw trick that doesnt seem obvious at first. and as usual i think the other teams can copy this techniqe without nweding much resources. Aldo Costa seems to have the talent of making big developments very suttle and hard to find on the car. I guess the teams can start scrambling to copy this kind of double diffuser. I also think this was mercedes interpritation of mclarens butterlfy suspension but they tied it into the diffuser.