First off disclaimer, I do not own either franchise
Pretty much enough said, I'm surprised this crossover doesnt exist yet as fanfiction, the idea is your basic fan get sucked into a world where the show is real, or a unfamiliar world with a kamen riders power from a toy becoming real.
Oc shift car optional
Single ship romance preferred, I mean come on its transformers no real need for a harem or anything
Oc transformers, I feel like most people dont explore the idea of adding new autobots or decepticons, you could have a predacon survive that explosion and be discovered by the reader, or have a rogue vehicon join the autobots
Jack Could become kamen rider Mach is a optional possiblity

OH LETS ADD SARI!

So there's your second chapter, and remember I dont own either series, and all we need is DRIVE

Drive, type Prime(actually that would make a great title)