I placed an order just now and a few moments
later remembered that I wanted another part
that would have fit into the shipping weight total.
It seems that once a transaction is finished, one can't ammend it?
Thanks. Great service!

Try bringing up you PartsShop account, then order history. I think you can update the order from that screen by selecting the most recent (unprocessed) order. Not sure what kind of time frame you have though.

Unfortunately, it works like this...
 

After the order is placed it is difficult to change it.

Some orders automatically go to a single supplier and others are manually split and go to multiple suppliers. Just because it says "pending" doesn't mean that the order isn't being processed. The actual path the order takes and the processes that are followed are all dependent on exactly what is ordered.

Ofter a simple change to an order means that we have to contact all suppliers involved, cancel the entire original order and place another order. The opportunity for error goes up in a major way! If we were shipping out of one warehouse that was totally under our control it would be simple but, to save time and money we ship directly from our suppliers to you.

It's kind of a good news / bad news story.

Thanks
 

Thanks Guys, I figured that it probably had complicated implications otherwise it would have been offered
as an option. No problem. I am happy to order from parts shop and even happier that the supplier is actually in San Francisco! Great! Well, if only Donnie and company were close by! :)