Funny noise need help

On route from galway to naas slowed down for toll and when I did heard this funny noise like a motor spinning for the world, as I slow it slows as I get faster it gets faster, so pulled of in balinaslo for a look around and nothing looks out of place, no oil under car but their is a smell of gear/diff oil , and pulling out of car park driveshaft / diff start to click, but car is going up motorway perfect no vibrations, no banging nothing but the noise, if I press clutch at 100kph noise still their ????? Any ideas please ????

Impossible to diagnose accurately over the interweb without a recording - and even then it is hard.

Sounds like possibly a bearing whining?

Best of try find a garage (or one of the traders on here) to have a look.

rear diff went in the legacy i had before, it sounded like an airplane overhead and it was scary as fook,i was travelling fairly fast when it did go.
From then on it would start to make noise from around 60klms
Take it handy till you find out hope its not to bad whatever it is.

Ya I'm swayed twords front diff or a bearing in the box, hopefully it get me home 2mor and start to find out Monday what the prob is, it's from the gear stick forward def not rear

Not that it would but I would bring fire extinguisher for trip home remember pauls impreza think it was the diff on the motorway. Gone in minute's, I haven't a clue but just to be sure. Hope its nothing serious lad

well droped of car today to elite autos to replace the box front diff was the cause of the noise :-(