Ever wonder where CJ's friends from Grove Street spend their time?
Now you can meet Sweet near his house (he will repair his car there), probably after CJ drove it. Near the house of the rapper from Grove Street, Og Lock and Big Smoke will stand and talk something (Big Smoke is his manager). Ryder will stand behind his house and smoke. Greenwood's car is parked near Sweet's house. Outside Og Lok's house is a Glendale car.
It is better to put the mod when you complete missions on Grove Street.