Phane, the routes you have defined have indistinguishable patterns. In your third example, search and registration have already been defined, and when you update search, you never stopped matching vehicals/:registration.
If you want to maintain that same pretty url structure, you will have to do so only using a single distinct pattern, then matching values. For example, this could be 'vehicals/:page'.
Also, it's worth noting that, while appealing for setting the screen, you're generally going to want to architect around the actual route attributes rather than the resulting pretty url.