Ya made me look!!
In 2007 Mattel used clear plastic in several different releases. There was the regular mainline Xraycers 4 car series and the 5 pack xraycers release. There were several other singles released. I think there were a couple singles released in 2006 that were called 1st Editions. If time permits, I will find a 1/2 case I have in storage of just those clear cars. Here is a quick pic of one of the 5 packs. Looks like I got too close and left off the top car. Correction will come tomorrow.

image

Steve, memory makes me think that there was also a release of these cars or adaptaions of them for Mc Donalds. You'll forgive me, I'm a 'lil older than Gunslinger.

"okie by choice"