Salutations:
Well, at the end of the day I ended up $660.00 (cnd) total (including purchase) on my three spoke NG/GM 5 bolt wheels. Much less than dealer replacement but more than I feel they were probably worth - rats - sometimes the SAAB gets you.
However - for the greater benefit of brother and sister SAAB flagellants to come - please be advised that the considered opinion at the end of the job was that three spoke NG/GM alloy wheels are inherently 'soft' alloy.
Thusly while your shop may feel strongly that they will break them in the straightening machine and may ask you to sign a waiver - they will most likely come back into shape and run much like clay through the machine without much heat in the hand of a skilled pro. Takes time and several passes though.
It was strongly advised that low profile tires be avoided in most normal conditions and that I should possibly consider a taller sidewall than factory spec if I can find a stiff enough sidewall offering.
There was a very bad flatspot on one of the outer rims when they arrived and a sub-contracting welding shop I ended up at probably used too much heat in the mistaken belief that they would crack otherwise - burning some wheel coating that didn't need to be lost.
When they got back to the straighteners (Scotia Tire - Halifax, Nova Scotia) to finish the inner rim - Scotia Tire passed the outer rim edges for a second flatspot and they were much more pliable then everyone had first thought. I could have saved myself the extra $75 (cnd) at the sub-contractor in the first place had we risked running outer rim lip in the machine in the first place.
That said, once all the wheels were straightened the ride and handling have improved - considerably - and greatly lessened road noise all round.
I also tossed in for an alignment at the end of job. We ended up setting the toe a little out on both sides (less on the drivers), which has stiffened the NG900 steering much more to my liking. Not as a snappy - but handles a little easier in everyday driving I feel.
Assuming all the normal disclaimers - please consider the above if you end up having to straighten your GM issue SAAB 5 bolt alloy rims.