If you find something strange on your car its probably a Quirk. If you are on the platform in your garage the monitor on the wall will show a yellow square on the bottom right.

To remove the quirk you go to the Tinker Station (to the right side of your car).
Here you will see 4 different rows and I will show you how you use them:

Lets use my problem:

When I was driving backwards, the hood opened.



Red: What is your input? -> Car
Green: What do you do? -> drive backwards
Orange: What part acts strange? -> Hood
Blue: What does it do? -> Opens

Then you press Spacebar and the machine will tell you if you guessed your problem correct.

If you found your problem you can now fix it. Easy right?

When you are inside the menu from the Tinker Station, press E and it will go to the next page.


There it will tell you what you need to fix your problem. In our case: 1 Sealing Kit + 1 Mechanic Kit.
if you have what you need inside your Inventory you can press Spacebar again. The screen will then start to swirl around in rainbow colors.

Congratulations, you just fixed a Quirk from your Car. :)


FYI:
- If this list has (like in my picture) 3 problems that means that your car currently has 3 quirks!
- there are useful quirks like "turning on dome lights make your headlights glow brighter" or "driving fast consumes less fuel/power" and other... its very important to save them (thank you Dubmaster for telling me)

On the normal settings you have 8 guesses to find out whats wrong. They will reset after you finished a run.

You can disable or at least weaken the Quirks in the settings menu.

If you dont want to disable them completely - later you can build upgrades for the station that will help you to find Quirks.

(This section is a copy from the comments. Thank you rhylser !)

You can brute force quirk detection.
There are 21 to 37 choices for column:
component (21 choices) action (37 choices) > component (21) action (33)

Start with the common actions as they can filter the components.
Example:
1. brute force cause action to be toggles (very common action)
2. This filters the car components . Brute force to radio
3. Now that you know the cause, experiment until you observe the effect:
radio toggles > dashboard flickers

Common cause actions:
increases, decreases, is full, is low, is empty, drains quickly, switches on, switches off, is closed, is opened, toggles, stays on, stays off, is detached, goes left, goes right

Common effect actions:
drains, consumes slower, increases, consumes faster, switches on, switches off, inverts direction, moves fast, moves slow, flickers, opens, closes, falls off, toggles, brightens, dims, wobbles


The quirk does not go away between trips. So if you fail in station, after the next trip, you can pick up again the quirk investigation from where you left it. You need a spreadsheet and lots of notes.

Find the quirk status: In the tinkerer screen press the 'E' (or top right) to see the list of quirk affecting the car. These quirks stay between mission and they are listed even if not diagnosed.

Investigating multiple quirks at once: The station upgrade that tells you if a guess is correct or not looks at all quirks. But the guess correctness checks also combinations.
Example:
car = cause for quirk 1
dashboard = effect for quirk 2
When guessing car and dashboard will be marked independently correct but not both at once.

Quirk minigame is extremely complex and very rewarding if you are a geek with a spreadsheet: at 4 quirks affecting simultaneously your car the probability is that will be solving at least one quirk per station visit.

I would be really happy if you rate this guide and if you have something that I should add to this guide then feel free to leave a comment!

Thanks again to Dubmaster and rhylser :)