Almost 300 cars were vandalized across Germany in a concerted campaign that was orchestrated by Russian-backed provocateurs for €100 for each damaged vehicle, to frame environmentalists and the Green Party for the vandalism ahead of the country’s federal elections.

their exhaust pipes plugged up with expanding construction foam.

Investigators said they found construction foam cartridges and foam guns in a van driven by three men just outside of Berlin in December of 2024. The discovery came after dozens of car owners reported vandalism to their tailpipes.

Russian experience with expanding foam destroying cars goes back to at least 2016 https://justacarguy.blogspot.com/2019/09/someone-is-seriously-angry-and.html 

https://www.kyivpost.com/post/46642

https://san.com/cc/attack-on-german-cars-was-a-russian-plot-to-frame-environmentalists-report/

https://www.swr.de/swraktuell/baden-wuerttemberg/autos-in-bw-mit-bauschaum-demoliert-100.html

https://www.reddit.com/r/UkraineWarVideoReport/comments/1iiz3q9/in_several_federal_states_of_germany_cars_were/

Back in 2020, was the first time I'd heard of expanding foam in the tailpipe https://justacarguy.blogspot.com/2020/05/if-youre-going-to-have-loud-exhaust.html