First of all, you have to swap 2 Chief Designers during the season.
Use one CD for the first 7/8 races (6 are enough), then you swap to another CD for the remaining races.
This will permit you to have 2 areas at the maximum initial value for the next season (50 points), and 2 areas with 33 points instead the single worst at 21.
CDs have strenght areas and weakness: you have to choose 2 CDs with 4 different areas (2 strengths, 2 weaknesses).
Pay attention that the best strategy is to have CDs with Acceleration as strength and one between Braking or Handling, but Acceleration is the "must-have".
As weaknesses, absolutely Reliability and Cooling System, they have a really low effect on the car performances.
So, in this way you will start with:
- 2 areas at 50
- 4 areas at 43
- 2 areas at 33
But now we have to analyze the bonus/malus given by suppliers.
The best thing to do is to choice suppliers who maximize the Acceleration area.
Engines:
- Murk: +10 Acceleration, -6 Fuel
- Tifosi: +10 Braking, -6 Fuel
- Toymotor: +10 Handling, -6 Fuel
- Rednote: +10 Aerodynamics, -5 Acceleration
- Wonder: +10 Fuel, -4 Acceleration
- Cosurworthit: +5 Tyres
Oils:
- Elves: +4 Acceleration, -2 Fuel
- Seashells: +3 Fuel, -1 Fuel
- Beep: +3 Acceleration, -1 Fuel
- Chavon: +2 Fuel
- Subtotal: +5 Fuel, -3 Acceleration
Tyres:
- Komehome: +3 Tyres
- Goodweek: +5 Handling, -3 Tyres
- Bridgerock: +5 Braking, -3 Fuel
- Donelots: +5 Tyres, -1 Handling
- Michigan: +3 Acceleration, -3 Tyres
Choose with attention your suppliers, because they change the initial values of your cars.
In my experience, the best thing to do is maximize the strongest areas of the game sacrificing the 4 with lower effect on performance.
So, I start the season with:
Murk+Elves+Michigan
In this way, I will have +17 points in Acceleration, -8 in Fuel and -3 in Tyres.
It's very important to maximize the Acceleration because it's the area with the highest impact in the performance of the car.
Even if you will have less points in Fuel and Tyres, don't worry, it would be not a real problem.
Why not choosing also other areas?
By two main reasons:
1) Because you would never want to permit your opponent having higher value than you in Acceleration, and
2) Because the gain in other areas will be too marginal compared to the gain you will have in a single area.
Obviously you could choose other suppliers, for example you could choose Goodweek instead of Michigan, so you will have +14 in Acceleration and others +5 in Handling.
This choice make you lose 3 points in Acceleration instead of Michigan, but Handling is also a nice feature.
I really discourage the other suppliers in the start of the season, because they don't let you to maximize the strongest area of the game.
Now, the spying strategy.
This is a mistery, because the game don't reveal you how much points you are late in every single area.
It's a lottery.
Obviously you have to invest only in areas under 100 and only if the icon is green (if is Red, you will not have any gain after the race).
How much areas choose?
It depends on your level and on the percentage you will have.
The best thing is never go under 11% because of the round effect.
So, choose one more area if the total is still over 10%.
In the first race, you have to choose Braking, Handling, Aerodynamics and Fuel (-8 is too much and you have to gain some points immediately).
At the end of the race, invest only in Acceleration.
This will let you having the maximum value (100) already at the 3rd race.
Remember that with +17, you have to stop at 83!
83+17 = 100
Race by race, increment Handling, Aero and Braking until the maximum value (combined with your bonus).
Maximized these 4 areas, concentrate on Tyres and Fuel.
When you are near to the max values, it's time to change suppliers!
Choose suppliers who maximize Fuel and Tyres.
You will lose the bonuses in the other areas, but you can immediately invest in them in way to reset them to 100.
This because at that point of the season you will not have to have any deficit in any area, even Fuel and Tyres.
Reliability and Cooling are not important, invest in them only in last races of the season!