Thank you?
I usually give a little "thank you" wave when someone lets me into traffic (or even if I wedge myself in) but sometimes I wonder if it could be misinterpreted. It was pretty common when I was growing up (up north), but I don't see it much lately and I don't know if it's a regional thing or maybe it's just a sign of the times.
Sometimes I wish I had a little sign in the back window with a few pre-programmed messages.
Originally Posted By SnoopisTDI:
Sometimes I wish I had a little sign in the back window with a few pre-programmed messages.

I'm ordering that and some truck nuts.
I usually just flash a peace sign myself.
This was all an extensive search of "hand signals" turned up.
Originally Posted By SteelTalon:
I do the wave of thanks
Well there's the ASL thank you...not everyone knows it though and if you do it to some Italian dude the he might mistake it for "fuck off"
http://www.lifeprint.com/asl101/pages-signs/t/thankyou.htm

The similar, but under the chin Italian gesture:
http://learn-italian-software-review.toptenreviews.com/top-ten-essential-italian-hand-gestures-pg8.html
Originally Posted By theworkingman:
I usually just flash a peace sign myself.
But then people might think you're a hippie.
