Banjo-Kazoomie was a prototype for the original Xbox which was started at Rare Ltd. in 2004. Players were able to construct their karts out of different parts, therefore after it was cancelled the concept may have evolved into Banjo-Kazooie: Nuts & Bolts, which was released on Xbox 360 four years later.
Brendan Gunn about this project:
“I’ve always wanted to do a racing game. I got to spend two weeks working on a prototype racing game for the Xbox. It was codenamed ‘Banjo-Kazoomie’, and it was a kind of kart racer, but you constructed the karts out of different parts, so I guess it was kind of a precursor to ‘Nuts & Bolts’. But for those two weeks I was doing the driving mechanics for it”