Be warned, this goes beyond car bombs alone
Car Bombs, Crude Bombs, Proximity Mines, Time Bombs, Detonators, WMDs. Exciting!

We can generalize a car bomb and call it simply "Bomb". It could be planted on a car, a suicidal maniac or simply a coordinate.
They need to be expensive and time consuming to manufacture.
How about the components required can only be acquired through smuggling. Since, smugglers can't really choose what they want, it would make collecting components extremely time consuming. It would also encourage trading between smugglers, as to craft an end product you would need a complete set.
They need to be effective. Explosions in VC don't have an overly powerful maximum though, so only players with < 33 health nearby would probably end up dying.
Lets add a few hundred successive custom explosions.....said Michael Bay.

I believe the "skill levels" and "experience" related stuff is against Argonath Vision, but I could be wrong.