Field guide

How to inspect a used Tesla for HW4 in 5 minutes

You do not need a scanner. You need daylight, 5 minutes, and the software screen. Hardware 4 is a computer and a camera suite — the window sticker will not say it.

1. 01

   60 sec

   Windshield cameras

   Stand in front of the car. Look into the camera housing at the top of the windshield. HW3: three similar dark lenses, no red. HW4: a high-res pair, often a dummy third, and a red / magenta tint. Look under good light or at an angle — the red reflection is the fastest clue.

2. 02

   45 sec

   Side repeaters

   Walk both fenders. HW3 has a black lens and a wider turn-signal LED strip. HW4 has a red-tinted lens and a thinner strip. Check both sides — replacements happen.

3. 03

   90 sec

   Software screen

   Get in. Car icon (bottom left) → Software → Additional Vehicle Information. Read Autopilot computer. Computer 3 / Full Self-Driving Computer = HW3. Computer 4 / AI4 = HW4. Photograph that line. This screen always beats the VIN reading.

4. 04

   45 sec

   VIN as backup

   Read the VIN on the windshield or door jamb. Run it on Hardoptic for factory, year, serial, and Supercharging context. Treat the result as a second opinion, not a title.

5. 05

   60 sec

   Walk away rules

   Seller will not open Software? Walk. Listing photos look red but the car is gray in person? Walk. They claim a HW3 → HW4 upgrade is coming? Tesla has not announced one. Do not price that in.