Good racing games on xbox for kids

Hey guys, just wanted some good recommendations for good racing games on the xbox (to play on the series x) for my 8 year old boy. Up until now he's been playing alot of Mario Kart 8 deluxe on the switch.

Was looking at the Lego dlc for forza horizon 4 as it's on sale for £6 at the moment. Any other recommendations will be much welcomed.

Thanks guys.