Ground bolt

[Draky]

So I noticed I was only getting 13.4 volts to the battery and the previous owner swapped out to 2.0T coils grounding the coils to the head bolt in the rear. So I'm thinking that the grounds in the engine may not be the best anymore and ran a ground from that same head bolt to the ground bolt on the front passenger wheel well and the bolt welds were weak and snapped off.

I'm wondering if it would be a good idea to drill it and do a new bolt through there for a ground or if there's a better one in that area of the engine bay someone would recommend?

Thanks again guys!