The general reaction? Well, as I recall from my history reading, in WWI, the Germans thought the Highland regiments were hilarious. In WWII, they saw the Highlanders roll up on (I think) Gold Beach, and almost imediately surrendered. So either you'll be laughed at or surrendered to.

(I'm just joking here- I have a few German pen pals who think it's awesome that I wear the kilt.)