I guess you are right. But I also bought my Signal Stat Arrow Turn Signal in the US, so what's the problem? But you have to pay attention to the price! I bought my heater for 100 € and then refurbished it. Were again 50 € ... But there are also people who charge over 800 € for the device! Way too expensive...
https://www.ebay-kleinanzeigen.de/s-wagenheizer/k0
I also have to admit that I have the 12V device and operate it with 6V operating voltage and a 6V step switch. The fan motor runs a little slower and the motor can stop at the lowest level. I am currently looking for the 6V motor that goes with it, which I would then exchange. But basically the system works first.