why dont semi'* have hid? their do alot of driving it would help them alot at night. cuz on the way home from school tonight i saw alot of cars that have them and i want them but i cant afford them. and i never see a car with hid that has a burnt out one their both always on. dont they break or burn up?

I can't answer all your questions, but I can tell you a standard halogen lamp like you have will last about 1000 hours, where an HID lamp will last about 3 times that long.

o ok thanx wow why dont more cars go with hid, cost?

There are people that dont like HID'*. The HID bulbs do go longer without being replaced. But also the true HID bulbs are very expensive. Some even get in the $150 range. So when you are paying that much for a bulb you want them to last longer. Plus if Semis had them can you imagine how bright they would be if they were behind you. Its bad now let alone if they had brighter lights.