Where to ground the after market deck?

[e30bimmer]

OK guys I just installed a new Alpine deck on my E30 but when the engine is running I hear whinning noise from the speakers. I was told that I need to find a good ground for the deck as short as possible and use no thinner than 10 gauge wire. Any 411 would be great...Thanks

[Jordan]

Ground it to the cig lighter brown wire.

[Digitalwave]

No head unit needs a 10 gauge ground... even 16ga would be fine.