Stryrofoam Gliders?

[J.Miller]

Every now and again I see men on the side of the highway into Ajijic sailing these toy gliders from one side to the other.  I saw them a few weeks back and wish that I had stopped to buy some for my young nephews.  Now my sister is getting ready to return to Canada for the summer and would like to take something home for the grandsons; she has found some pretty tapestry backpacks for the girls but boys are harder and we are thinking that they would love the gliders.  Does anyone know where we might find them?  They look to be about twenty inches from nose to tail, so they are a good size and I am guessing that they are made from Styrofoam.