redline is the factory's idea of the engine's limit. 
sometimes they buid em better than they think, 
and you can go over the red line usuing a chip.
however DO NOT shift into 2gear when you're 
going 100mph, no chip or electronic rev limiter
will save you there =]
its good to rev your engine it helps reduce carbon
buildup (which is produced at low rpms) and also
keeps your injectors a little bit cleaner when you
go WOT