Like most Scalextric cars they work well on four wheels except these are supposed to have six and two of them don't but as a repair ready wonderful project with little to do but order/find the spare parts (please see spare parts I am selling). 
When these cars are perfect they are worth good money (please see perfect version I am also selling).
Now over to our resident Scalextric expert, aBay the eBay AI......

For sale is a trio of Scalextric March Ford 771 cars in their original blue livery. These cars are pit lane ready and perfect for any racing enthusiast. Made in the United Kingdom in the 1980s, they are analogue and come with the Rothmans branding. The cars are in great shape* and will provide hours of fun for anyone who loves slot car racing.

*she means they still look like cars, please see info for their actual condition.