In 4th edition's supplement Arsenal, there were rules for Indirect Fire. Initially you had to determine if your round guided itself or not. They had this broken into "Information-Guided" and "Target Designator-Guided" attacks. Then the spotter had to maintain the lock or sight line. Once you had determined the guidance method, you used a standard attack test and took a penalty based on which guidance method you used. Net hits would reduce scatter until the scatter became 0. Additional hits beyond that point added to DV.
I would assume that Run and Gun will have rules on indirect fire, but overall the system isn't too complicated. The spotter has to lock on to the target with a sensor test, net hits being used for extra dice on the attacker's test. Not too bad.