I bought 4 of these from banggood for about $8 each with free postage and gave a couple to my niece and nephew, they are great little cars.
I changed the tiny nimh inside of one to a little 1s lipo i got out of an old pico-z and it is wild! I chopped out some plastic and took out the charge port so i can fit the lipo inside.. i charge the lipo on the pico-z tx.
One of the drive wheels was not touching the ground which made it turn when i pressed forward. So i added some tape under the tire to even it out and now it drives straight. Quite fun
Will post some video soon.