I was trying to get my basic Explosives Ordinance badge last night by loading C4 onto a buggy and kamikazi-ing armoured vehicles. I succeeded in the second round that I tried - and I ended up getting my basic transport as well
I must have really annoyed the hell out of some people tho

I killed the same people several times while doing it.
I also developed a new technique (for me anyway) - the flying bomb - I loaded up a blackhawk with C4, flew to a nearby enemy base, hovered over some guys, switched to F6 and blew the C4.
Works quite well
I also noticed that it is far more effective, score wise, to remain in your vehicle when you kamikazi. If you hop out and still get killed by your explosion you will lose more points.