hi brother just bought a focus rs

, there seems to be a funny noise the very odd time.
the noise comes across as a whistle/like a firework launching!!
is anyone aware of this?there is only 15000 miles on the car and is standard.
Another thing is the drooning road noise from all round, sounds like a wheel bearing, is it knowen to be a noisy car?we are putting it down to cheap tyres(wanli's)!!!!!!!!!
Anyone know?