Typically not starting isn't the ground bus. Does it crank and not start, or does it click and not crank? Click and not crank tends to be problems with the battery cables. Remove and clean both ends of both cables and put a little dielectric grease on the connections. These need to be cleaned at least once a year.

I seem to remember there being a ground in the back near the trunk.

On other forums, I found ground locations for 97 Bonneville & other Pontiacs.

1) Ground bus (wrapped with black electrical tape) under carpet right next to the front-most side of each of the 2 front door openings. Apparently there are 2 ground buses, but I found my intermittent starting problem was caused by the ground bus that'* next to the driver side. Specifically, it was caused by to a corroded ground wire connector that'* next to the end ground wire (fattest). Note that there'* an empty connector slot between these two wires/connectors.
2) Rear of the engine block near the oil pressure switch.
3) Left front of the engine compartment near the air cleaner.
4) Bolted ground connection under the glove box by the front of the door frame.
5) Grounds to the block under the Ignition Control Module (ICM), located under hood, mounted on upper front passenger side of engine.

Dude, go read the rules that were given to you in your welcome PM. This thread is 7 years old.

If I'm not supposed to reply to old postings, then I'm sorry, and I can delete my reply if you want me to.

Often times, when I search for a similar problem that I'm having, an answer is most likely not found in a recent posting, but one that'* very old. It doesn't matter to me if a posting that can help me is a recent one or a decade old (my car is 20 yrs. old). As long as I find an answer to my problem, I'm happy. I'll bet others feel the same.

Also, the "other postings" I was referring to are not on gmforums.com, and I'm not violating any copyright laws.

Generally, the accepted practice on most forums is to generate a new conversation regarding your specific issue, and link back to previous discussions. The underlying concern is that it not only potentially stirs up unnecessary conversation with members whom will never respond because they have since moved on, but it also can cause confusion, because, while issues may be similar, or apparently the same, each individual'* solution may be different.

Well said, and exactly my thoughts!

And had you read ALL of the rules, you would have understood the real reason and not just guessing about why we frown upon it.