If you know the reference number that was printed on the key, we might be able to obtain a replacement key. If you don't know the key number, you best bet would be to drill the lock cylinder out, or use a cut-off wheel on an angle grinder to cut the lock off flush with the side of the receiver tube. If you don't feel comfortable doing this, your mechanic or locksmith should be able to do it with no problem. view full answer...
The Putco Pure Premium LED Bulbs you mention, part # P343157W-360 is the correct replacement for the original # 3157 bulbs used in the daytime running lights on your Enclave. They will fit just fine.
Resistors are not necessary, because the bulbs aren't being used to replace turn signal bulbs. view full answer...
The Roadmaster # RM-910003-40 Inner Arm Bushing Kit for Sterling Tow Bars you referenced does include replacement bushings for both arms. view full answer...