I'm definitely gonna cook up some custom pharmacological fun for my dwarf street sam. But I think there's going to have to be a houserule about the "enhancements" adding +1 to the addiction threshold each. Having a drug with an immediate effect shouldn't need a threshold 5 addiction test, when kamikaze is only 3
Also, definitely getting some K-10, for when you're willing to have a very bad day to ensure someone else has a worse one.
Not really an auto-injector type thing, but NoPAINt also looks quite fun. Reminds me of the warpaint the vikings used to wear that turned out to contain small amounts of a natural compound analogous to PCP.