Model 3 & Y Taillight Condensation and Trunk Leaks: How Owners Got Them Fixed

Owners were told the housings breathe through a Gore-type vent patch, so a light mist after a wash that clears again is expected ^[2][6]. The rules service gave them varied a little: one owner was told fog should clear within two days or about an hour of driving, and got a replacement when it lasted three days ^[2]. A moderator summarised the working rule as replacement once the mist turns into droplets ^[4].

A mobile tech told one Model Y owner that fog in both lights is normal, but fog in only one is a sign of a bad unit ^[3]. Another said pressure washing can force water in through the small vent hole in the housing ^[1].

An Australian owner uploaded photos in the Tesla app after fog lasted more than a week following heavy rain. Tesla approved a free replacement the same day, the part arrived about a week later, and a mobile tech swapped it at home in under ten minutes ^[4]. A Model Y owner had the same ten-minute swap ^[3].

A 2023 Model 3 owner was advised to log timestamped photos showing moisture over one to two weeks; one member got a seal replaced under warranty that way ^[6]. Not every service center agreed: a new Model Y owner was told his fog was within spec ^[3], and another service center refused unless water collected at the bottom of the lens ^[2]. Replacements can fog again too; one pre-Highland owner had both lights replaced twice ^[6].

One owner removed the lights himself and sealed them with liquid tape. It looked good a day later, but some fog came back after a wash, and he warned that the trim clips break easily ^[1]. Another fixed a light following a YouTube video, carefully peeling and reattaching the vent sticker ^[2]. If the car is still under warranty, the replacement route is simpler.

An owner just out of warranty found water near the rear left light or trunk seal and planned a hose test with a helper watching from inside the trunk, which is the simplest way to find the entry point ^[5]. Another had two trunk leaks fixed under warranty, both with a new trunk seal ^[5]. One owner with fungus in the lower trunk had the seal replaced and ran a small dehumidifier that pulled about a cup of water a day ^[1].

A later member cited a Tesla service bulletin that calls for sealing the trunk-lid seams and fitting thicker gaskets behind the lamps, and said water gets into the lid and then runs into the trunk; his leak persisted through several warranty visits ^[5]. A 2026 reply pointed to bulletin SB-24-10-008 on liftgate sealant rework, written for the Model Y ^[6].

Every replacement in these threads was free under the basic warranty, usually by mobile service ^[2][3][4][6]. No thread reported an out-of-warranty price, so get the lamp and seals looked at before the warranty ends. If you buy a lamp yourself, confirm the part number against your VIN; numbers differ between early and later builds.