Your son needs to have direct, measurable consequences for such behavior. Typical punishments include time outs, losing privileges, natural consequences, and logical consequences.
It can be hard to give time outs when in a car, but other consequences can be had. Your son is old enough to understand that current behavior can cause future punishments, so he could receive some logical consequences or loss of privileges.
These examples apply directly to the situation (logical consequences):
- He's going to have to clean the car seat himself
- If the cleaning requires buying new cleaning supplies, he may have to pay for them (from current or future allowance/chores).
These are generic examples that could apply to behaviors that don't have direct punishments (loss of privilege and logical consequences):
- 15 minutes less screen time that night per time you tell him to put his feet down
- Has to do an undesirable (but reasonable) chore once he gets home
- Can't go to a friend's house that night
It'll be important to be consistent. When your son is intentionally being disobedient, just for the sake of being obstinate, he'll need to have a consequence appear each time. The consequences should be delivered in an calm, assertive, matter-of-fact tone. "If you put your dirty boots on the back of the seat again, then you're going to have to scrub it tonight."
Initially, you may not see immediate results. If he doesn't have any historical reference to work from, he might not believe you'll follow through, or he might not realize how not fun it is to scrub a car (or whatever punishment he receives).
After you've given out consequences like this once or twice, he should understand that you'll follow through and the consequences are not desirable. However, he may still persist in unwanted behavior. So, you'll have to up the ante on the consequences, while still maintaining your cool exterior.
Going back to the dirty seat, for example, you could increase the consequence in the following ways:
- He has to clean it and pay for the supplies
- He also has to clean the rest of the back seat (scrubbing/vacuuming, throwing out garbage)
- He has to go with you to the store to get the (boring) car cleaning supplies
- He has to do any/all of these things before he can do any fun activities, like screen time, playing outside, etc.
I also mentioned natural consequences, but they don't come into play easily with active behaviors such as this. An example of a natural consequence for obstinate behavior would be refusing to put his snow boots on, so he has to wear his regular shoes and get cold feet, or he delays leaving until he ends up being late to class.
Lastly, it'll also be important to reward or recognize your son when he goes long periods of time without exhibiting the undesired behaviors. It's important that this feedback is sincere, not forced or condescending. I would also encourage you to give positive reinforcement to your son while he's doing any cleaning/chore punishments. That is, instead of saying things like: "Scrub harder" or "You missed a spot", you can say "You're doing a good job of scrubbing hard" or "You're doing a good job of working on that tough spot. Why don't you let me finish up that spot so you can work on X and be done sooner."
By being encouraging, even during his punishment, you'll help to:
- Alleviate negative feelings
- Help boost self-esteem and work ethic
- Create an environment where he knows he's being observed and supervised, but not micromanaged and commanded