earthing point in the dash

[Slowlysideways]

Hello, just re-fitting some switches on my dash as they are currently housed in a seperate box. so Im looking to re fit them where the headunit is. just wondering where the nearest good earthing point is.

thank you, be kind Im a newbie.

a picture to help ............

 

[rubjonny]

iirc there is a stud on the inside of the a pillar, this would be a good point