Reducing a cars rating through tuning?

Hi, I need a little help with something. I’m trying to get a formula E car down to A class. I think they are all exactly the same but I am using the dragon racing one. So far I have managed to get it down to 703 through upgrades. For the last 3 points, I think the only way to do it is through tuning somehow. If anyone has any idea how to go about this, suggestions would be great.

Upgrades only effect pi. tuning has no effect pi.