Acceptance of changes according to § 19 (3) StVZO

However, [...] the vehicle's type approval does not expire if, in the case of modifications [...] for these parts, acceptance of the installation or [...] installation is promptly performed by an officially recognized expert or inspector for motor vehicle traffic or has been carried out by a automotive expert and [...] confirmed that it has been properly installed or installed. [...]
Here are conversion measures on your vehicle, e.g. special wheels or a vehicle lowering etc. taking into account e.g. a parts certificate on the proper installation and in writing for the supervising authorities e.g. the road traffic registration office or the police authority confirmed.