One of my headlights needs replacing but I've no idea if it's xenon or halogen how can I tell? 

    HALOGEN BULB XENON BULB

I took it to an audi garage and he said 240 quid to fit a new xenon bulb.  I went halfords and theye are saying I need to replace 2 bulbs. I'm genuinely confused now! Could it be that it's not the bulb but something else causing it to go? I've got an extended warranty but it doesn't cover bulbs 

with an sline, it should be xenons

 

The light starting working again the other day but is now not working. I took it to my local garage he said I'll need to bring it back to him to have a proper look. Audi want 60 quid just for looking at it. Has someone on here had a similar problem If so what did you do about it? 

I would say have a fiddle around with the wires to see if there is a loose connection but as it is around 25000 volts when the ballast fires up so be very careful.