You'd certainly need to move. You'd also have to be keen to roll up your sleeves. A new design comes alomg once every 8 (?) years so the rest of the time you'd be employed as a mechanic/draughtsperson. From a factories point of view it isn't really worth employing a full time design engineer so I would suppose that most are employed on a contract basis.
Have a look through the back issues of MX digital. There was an interview with one of their design engineers in one issue. Curiously he's a yank. AFAIK he started working in a Gas Gas shop and worked his way through uni, ending up with a masters in engineering, he then went on his OE and picked up work for Gasser where his design talents were noticed.