I gave up on getting either robot into vehicle mode out of frustration.
Combining the two was nice and easy and the resulting Battletrap is a good looking combined robot. As individual legends though both are far too compromised for my liking. I concur with Lint the instructions are hard to read and were of no help.
Disassembling Battletrap into two vehicles was easier. I missed a hinge on Battleslash and Roadtrap fit together better once he was already in pants mode. Overall I don’t like either as an individual legend so I vote only if you want a Battletrap.
It is named in the instructions as Duocon Battletrap.