I could only find two references to them in all of the SR4a books:
" If you’re looking for big firepower, talk to a dwarf named Otto
who’s got a gun shop down at the south end of the second floor.
He’s connected with the Red Hot Nukes and he can get you some
major bang-bang. Tell him I sent you.
- Beaker"
Runner Havens p. 117
"Redmond at a Glance
Major Gangs: Brain Eaters, Crimson Crush, Red Hot Nukes,
Rusted Stilettos, the Spiders"
Seattle 2072 p. 114
That one is strange because they List them in the 'Redmond at a Glance' section, but they are not in the full Seattle Gang listing later in the book.
I had thought that some other gang (like the Rust Stilettos) wiped them out?
And of course, their Shadowrun Wiki reference, which was probably pulled from 3rd.
http://shadowrun.wikia.com/wiki/Red_Hot_Nukes