i don't mean to sound rude, however 4 15" tubes will hardly light up the undercar of an explorer.
Street Glow's Gold Series (which i would recomend over the blueline....the blueline series is dimmer, harder to instal, and does not carry the Lifetime warrenty) is easy to instal, durable, has a lifetime warrenty (as long as lexon does not brake) and includes a 9500v transformer, (2) 30" tubes, and (2) 54" tubes
I still had a few dead spots under my explorer so i put a few extra tubes underthere to kill them
Carleton