research is confusing

I am new to game. I researched the chassis expansion and then bulldozed the chassis assembly and rebuilt it into the three new sections… then when my vehicle hit the next slot it all SHUT DOWN because the cars had NO BUMPERS?? What is the solution? I don’t think it should work like this. Also I keep getting notices that rival companies are researching stuff but I DO NOT SEE THAT STUFF on my research tree. I appreciate the you tube tutorial but wish there was a written instruction manual also. Thank you, Joan in Michigan USA

I see your Quick Start and FAQ post… maybe you could get a page like this on the GAME MENU??