u/Motor_Ad9605

Hey im interested in buying a 99' Lexus RX300 that I will only ride on the highway and i'm wondering what can be done to improve the fuel economy. I have seen dinner plates on wheels and rear wheel covers and diffusers but by how much do these modifications improve fuel efficiency and how can one make (or buy) them? Thanks

Hey guys I have some extra credits, last year I took German with David Gramling and it was my favourite class ever because he was such a good prof and also just gave us all good grades... Anyway, this is obviously a difficult question to have an answer to but how are the 100-200 level French profs? I would just prefer to learn French over German.