The Sizzlers were a series of very cool looking Hotwheels cars made by Mattel starting in 1969. These toys had a rechargeable battery contained within a cool and often colorful plastic body. These cars would run quite a few times around an oval track on a single charge.
Many car designs mixed with many body colors lead to a plethora of different cars to collect.
It is quite amazing to me how few people even remember this series of toys. Perhaps it was because they were constructed of lightweight plastic instead of metal like their counterparts. I still have two cars in running condition today, although most of the batteries in my other cars have long since rotted away. I recently found a chrome plated modifies van Sizzler at the local flea market in with a bunch of hot wheels but this was the only one I have seen in several years of looking. My Mustang and Van are both chrome.