Big fat tyres.

Big fat tyres are back in F1 for 2017. A step in the right direction-more mechanical grip and the tyres will apparently be designed to perform not purposefully degrade. First photos of 2017 cars show that they look so much better see 2017 car
Next they need to cut down on the aero. Aerodynamic grip and stupid tyres have ruined Formula 1 in the last few years..
One from my archives - the Leyland P76 V8 powered F5000 Unipart McLaren of John McCormack back in 1978 when tyres were also big and slick.