1. First, make the car look like 2008 season, but wider (as wide as the late 80s - mid 90s cars & the current 2017 F1 cars which is 2m wide instead of 1.8m wide) and wider thicker tyres (as wide and as thick as 2017 F1 tyres). And larger wheel diameter (as large as Indycar's wheel). Add a little bit of 2017 F1 cars' improved aerodynamics is fine, but don't change the 2008 F1 car shape. Also, flexible parts of the chassis like Red Bull used to have on their 2009 car flexible front wings and like Ferrari had earlier this year on their flexible floor. What's wrong with it if it makes the car faster? It should be allowed and instead it should be the new regulation!
2. And then, bring back the V10 engine. But, make the V10 engine 3.6 l instead of 3.0 l or 3.5 l. With the angle of the engine remains at 90°. Also, don't put rev limiter on the engine, don't put limitation on the oil burn, and don't put limitation on the exhaust flow if it makes the car slower. Not just that, these kind of regulation actually killing innovation!
3. Stop making the tyres degrade easily. More pit stops doesn't mean more exciting race if the drivers can't always push the cars to the limit just for saving the tyres.
4. Last but not least, add Quad (4) Turbo Chargers, Quad (4) Super Chargers, Formula-e Electric Engine, Formula-e Electric Motor, Formula-e Electric Battery, ERS (Energy Recovery System) with MGU-K and MGU-H, Dual (front and back) DRS (Drag Reduction System), Blown Diffuser, ABS (Anti-lock Braking System), TC (Traction Control), NOS (Nitrous Oxide), Methanol, radiator, and 360° T-Cam.