How to fully upgrade my car?

[Insterestellar]

I already fully upgraded many cars in Need For Speed: Rivals, but when I saw my statistics, only one car was fully upgraded (I don't really know which one it is), and I got many cars fully upgraded (5 at everything: top speed, durability, etc) just as Ford Mustang GT, Lamborghini Aventador/Veneno, McLaren P1, McLaren 12C Spider, Ferrari 458 Spider, and many others. Does anyone know if there is something I need to do to FULLY upgrade the car performance? 

Also, when I complete a speedlist, it says that there are more peaces that you can use to upgrade the performance of your car but I don't see any of them, is that related to the fact I can't fully upgrade the cars?

Thank you!

[Schmik24]

I got the same problem, I know that there are 2 cars at least with which everything is at the max, but my cars fully upgraded line reads 0/22.

Did you find a solution?

Can it be that we need to set a certain type of stripes/Wrap/whatever in the car personalisation thingy?

Thanks in advance

[Jacobba55]

@Schmik24 You may need to buy all the pursuit tech upgrades on a car, in order for it to be counted as fully upgraded. I don't think it would require all the visual customization, as that would be extremely expensive...

[Jacobba55]

@Insterestellar If you mean fully upgraded in the sense of filling the performance bars completely, then it just isn't possible on most cars as they can't reach it. Even with max upgrades (5 of 5), only a select few cars can fill even ONE bar. I think the Koenigsegg One:1 has Top Speed rating 10.0 with a full bar, but I'll check the others too, if required.