How to Get Crystal Clear Glass (Without the Streaks)

Don't even bother trying this if the glass is hot to the touch. The cleaner will evaporate before you can wipe it, leaving spots. Find some shade or wait for the arvo.

Run your hand over the clean, dry exterior glass. If it feels like sandpaper, you've got bonded contaminants (sap, salt, dust). You'll need to clay bar it first.

Wind your side windows down about an inch. You'd be surprised how much grime hides in that top channel. Clean that edge first so it doesn't smear the rest of the window later.

Give the outside a good blast with the hose to get the loose Aussie dust off. If you've been near the coast, this is vital to get the salt crystals off before you start rubbing.

Use plenty of lubricant (soapy water works fine) and run your clay bar over the exterior glass. You'll hear it 'scratching' at first, that's the dirt coming off. Keep going until it's silent and smooth.

Spray your cleaner onto the waffle weave towel, not the glass. This prevents 'overspray' getting on your dash or trim. Wipe the glass thoroughly.

Immediately follow up with a second, dry microfibre. This is the secret. You aren't just drying it; you're buffing away the microscopic residue.

The inside is usually oily from the plastic in the dash 'off-gassing.' I reckon a quick wipe with a 50/50 IPA/water mix first is the only way to cut through that film.

Sit in the passenger seat to clean the driver's side and vice versa. It gives you a better angle. Use your reach tool if you can't get right into the corners where the glass meets the dash.

Wipe the outside glass vertically and the inside glass horizontally. If you see a streak later, you'll know exactly which side it's on by the direction of the line. (A mate taught me this years ago, saves so much time).

Move your head around and look at the glass from different angles. Use a torch if you're in a garage. If you see a hazy spot, give it another dry buff.