I have used carbide lighting extensively, it is still not quite a defunct technology for caving use.
Here, for example, is a brand-new caving light set: http://www.trolluk.com/outdoor/head-touches/item/86-acetylene-cavers-lamp
The flame is quite cool (takes ages to burn through a rope, luckily) and the gas is pungent enough that you are unlikely to build up a dangerous concentration without noticing.
The best light for vehicle use uses two impinging flames, and is very bright without any need of a mantle.
It's a lovely light to cave by, though I haven't yet tried driving with it (I am at the moment part way through making a lighting set for my 1921 Ner-a-Car, which has dual electric / acetylene lighting).
You can get carbide from various sources still, including Amazon and eBay.