Many States allow of personalized license plates. Here in California, they are called Vanity plates. I got “Z 1:220” (you can’t order with the colon so I left a space and then used yellow vinyl dots. I also ordered a Germany plate from Amazon, Spur Zed (could not find a supplier that would do Upper/lower case. One could do ü but the plate design was crappy. So I was going to the local markets and when I merged into traffic I soon hear this awesome loud horn! Sound like a multi-tone train horn (the UP mains are quite close by). Looking behind me, no big Rig trucks just the typical ‘I have to have a big truck’. About half mile ahead, we again slow down in traffic when I hear this even better AWESOME 40 year skilled horn puller that was now behind me ! Musta figured out my plates and a local railroader!