>>3221222 (lb)
Putting tack-on logos is common in China. I could be wrong but I highly doubt there is a Mercedes ZZR.
Except that in this case, the 3 women all worked from the same org, and definitely had it in for your lawn cutter. And previously, the same org had organized itself to take down other lawn cutters. In that case, you could conclude that the lawn cutter was probably ideal, and they must have some other reason for hating him.
>zzrparts.com/gywm.html
Way more likely it is just some random letters, IMO, or the logo of a 'tuner'. Think about it, Mercedes doesn't name their models tacky things like 'ZZR'.