I would guess Aston Martin could probably do very little sand bagging, I am guessing that they will want to show the world that they are getting much better.

I mean sand bagging is when you do not want your opponents to know how good you could be, and that is why Aston Martin doesn't need that, they are not a good team at all, and if they show off, and look better, there is nothing that other teams can do after this point anyways, and if they do suck, then it is not going to matter since they are already bad. Aside from that, everyone will just be a bit slower than their usual tests, that's it, they will just be a few seconds off, and that is all for everyone, not just one team, so nobody will show their 100% real time, not a single team.