The penalties for taking the law into your own hands are generally highly asymmetric and in favor of the original perpetrator.
For example, if you forced the car thieves out of the car, or parked it in place by blocking the road, you might be looking at assault charges.
Similar arguments can be said for most other common crimes.
Consider noise ordinances (harassing / threatening your neighbor until they shut up), trespassers (Threats? Forcibly move them?), burglaries (rob them back?), domestic violence (victims that kill the assailant are often charged with premeditated murder), etc.