Switched at Birth.

[Sky Shadow]

Sunstreaker and Sideswipe's abilities in their bios seem to have been mixed up at some point.

Yeah, that's what I suggested at the beginning - Budiansky definitely wrote the bios with Sideswipe supposed to be the red Diaclone Lamborghini with an exposed engine supercharger, shoulder mounted missiles, jetpack and piledriver fists, while Sunstreaker was supposed to be the sleek yellow Diaclone car with a single shoulder-mounted missile launcher. In some of the early comics the vehicle modes were switched that way, resulting in this:



And yes, they seem to share the same robot mode other than the jetpack, while Sunstreaker has a Decepticon insignia.