Where do people get surplus F1 teamwear?

[fastcaterham]

I always seem to see plenty of people with what appears to be surplus f1 team wear such as gloves, boots and even suits. Has anybody on here got any and if so where did you get them from? I'm specifically after some luminous yellow alpinestars gloves as worn by Rosberg but the only guy I've seen with them was a bit vague and just said he had a mate who worked for Mercedes GP. Has anybody had any luck simply emailing teams and asking or do they just sell them off at the end of the year?