Philips car lamps are made of high-quality quartz glass
UV-Quartz glass is stronger than hard glass and highly resistant to temperature extremes and vibrations, which eliminates the risk of explosion. Philips quartz-glass lamps are able to withstand severe thermal shock. With the capability of increased pressure inside the lamp, UV-quartz glass is able to produce a more powerful light.
Philips car lamps are highly resistant against humidity
Only a burning bulb made of quartz glass can resist thermal shocks : if a drop of cold water touches the hot bulb, which can happen when you drive through water with a broken headlight unit.