I'm "playing cars" with my 3 year old grandson. He was bringing me his. All 55 of them, one car at a time. Its fun. A new collector is born.
He has me stumped on one of his. A little slide button that doesnt do anything.
http://i174.photobucket.com/albums/w96/bob8748/question001.jpg
Made by Mattel, release date 2005. MFG. For McD CORP.
This little button or slide thing is on it.
http://i174.photobucket.com/albums/w96/bob8748/question002.jpg
It doesnt do anything, but I'm sure it is there for a reason or it wouldnt be there. This is going to drive me nuts!
Any idea what this little slide switch is/was for?

The most recent Mcdonalds Hot Wheels had a car with a similar switch that would turn on a small LED light inside the car. Look on the bottom of the car. Does it have "Made for McD" or something similar on the base? It might be a Mcdonald's or playset car. Perhaps the battery is dead. Judging from the clear parts of the car, it's probably a light-up car. The light could be defective, as well. Hope this helps.

Sorry, I didn't read your post carefully to see that you did see "Mfg for Mcd Corp." on the base. It's a light-up car and that's the switch.

If for any good reason its fun. He pointed at the monitor and said "thats my car!" upside down pic was "wrecked".