Yes, the hooks come with most cargo nets for Lexus and Toyota
passenger cars. Oddly, although they look the same, the cargo net hooks that came with the cargo nets for our Camry and Lexus LS have different threads -- you'd think they'd be interchangeable on two cars made by TMC but they aren't.
Some
Lexus SUV's have come with the cargo net hooks already installed. I wonder if any of them would work on your SC. If you have an assortment of metric bolts, you could pop out the two plastic trim holders where the hooks would install and identify the bolt size and thread type.
Maybe cargo hooks from an LX470 would work. Take a look at the "HOOK, LUGGAGE COMPARTMENT" in this 07 LS470 diagram:
http://www.toyodiy.com/parts/p_U_2007_LEXU...NAGKA_6451.htmlClick on the text in the parts list on the right side of the page and the part in the diagram will be highlighted. Maybe part number 64725-60010-A0 (ivory) or 64725-60010-B0 (stone) would work. Maybe see if your local Lexus dealer has one of these in stock that you could try.
Similar looking cargo net hooks are available for the GX470:
http://www.toyodiy.com/parts/p_U_2007_LEXU...KAZKA_6451.html64725-60020-A0 (ivory) and 64725-60020-B0 (gray)
That's all I can come up with for now.