Wow, they all sound amazing! I don’t know much about any of those – I know people are definitely working on creating robots (some human-like androids, and others designed to be different from humans so they’re better at other things).
Gravity defying cars are a trickier one. We already have gravity-defying trains, though – the MagLev trains in Japan use ‘magnetic levitation’ to float above the tracks. The tracks are magnetic, and the bottom of the train is lined with a special material called a superconductor which needs to be cooled to -200C to keep the train floating! If we manage to make ones that still float when they’re warm, we could have gravity defying trains!
As for neon extra speed sports cars, I’ve no idea, but if anyone ever makes them, I really want a go in one!