Although there are many models of the Vauxhall Astra, the process for adjusting the headlights is very similar. Unlike many vehicles, the Astra has two adjustment points that are turned with Allen keys. Most vehicles have either turning rods that you move with your hands or a screwdriver. Either way, adjusting the headlights correctly is essential to driving safety, as poor visibility can endanger everyone on the road.
Park your Astra facing a flat vertical surface, such as a garage door, 7.5 m (25 feet) away.
Turn on the headlights and prop open the bonnet.
Look for the two hexagon-shaped adjustment points behind the headlight you wish to adjust.
Insert your Allen key into an adjustment point to change the vertical or horizontal aim of the headlight. Adjust the aim so that the headlight hits the ground where the ground meets the vertical surface the Astra is facing.