What alterations can result in the permit for use (Betriebserlaubnis) being cancelled?

Your selection of options 1 and 2 is correct because both fitting a sidecar and fitting tyres of a different size can compromise the vehicle's safety and performance, leading to the cancellation of the permit for use (Betriebserlaubnis) under German traffic regulations.

In Germany, any significant alterations to a vehicle that affect its structure or behavior, such as adding sidecars or changing tyre dimensions, must be approved to ensure compliance with safety standards. These modifications might change how the vehicle handles, how it responds to braking and steering, and can affect overall road safety.

Fitting a rear fog lamp, on the other hand, usually does not affect the vehicle's fundamental safety or performance in the same way and generally does not lead to the cancellation of the permit. Therefore, it is important to identify all relevant alterations in order to fully understand the implications regarding vehicle safety and compliance with traffic laws.