An Aircraft Engineer is someone who is Licensed and makes decisions every day and takes responsibility for the aircraft where as An Aircraft Mechanic is an un-licensced guy who where, they do still do a lot of the work don't take responsibility or make the same judgments that the person who has gained the qualifications does.
Where as a car mechanic may do an HNC it is a far more advanced course to gain a Licensce and then go on to gain types on top of that, Plus your normal Aircraft Engineer will drill/rivet/do sheet metal repairs, use complex test equipment and fault diagnose multiple complex systems.
So to me a fully qualified Licensced Engineer deserves the title and should be respected for their qualifications and Knowledge.
NST