A sunshade — the best of the lot
Unglamorous, cheap, and it outperforms every interior product sold. It blocks the UV before it reaches the dash and keeps cabin temperature down.
Use it whenever the car is parked in sun, not just in summer.
Dashboards fade and crack because UV breaks down the plastic and drives out the plasticisers that keep it flexible. Heat accelerates it. Once a dash has cracked, nothing reverses it — this is a prevention problem with no cure.
Two things genuinely work: a UV protectant on the plastics ($25 to $45 depending on vehicle size) and a sunshade. The sunshade costs almost nothing and outperforms every product on the market.
The most common myth here is that San Francisco is too cool for this to matter. UV is not heat, and overcast days transmit plenty of it.
A dashboard is a polymer with additives in it — plasticisers for flexibility, pigments for colour, and UV stabilisers to slow all of this down. Those stabilisers are consumed over time; they are not permanent.
Once they are used up, UV starts breaking the polymer chains at the surface directly. The plasticisers evaporate out, which is the same process that puts the oily film on the inside of your windscreen. What is left is a surface that is drier, harder and more brittle than it started, with the colour going chalky as pigment degrades.
Then normal use finishes the job. Every heat cycle expands and contracts a material that has lost its flex, and eventually it splits — usually at the top of the dash where sun exposure is most direct, and around the defroster vents where the plastic is thinnest.
The San Francisco misconception is that this needs a hot climate. It does not. UV and heat are different things: a cool, bright, overcast day still transmits substantial UV through glass, and windscreens are angled to catch it. A car parked outside on a west-facing street here accumulates plenty of exposure over five years.
What this city adds is the fog cycle — damp overnight, sun in the afternoon, repeatedly. Repeated wet-dry cycling on a surface that is already drying out is not doing it any favours.
In order of how much difference they make per dollar.
Unglamorous, cheap, and it outperforms every interior product sold. It blocks the UV before it reaches the dash and keeps cabin temperature down.
Use it whenever the car is parked in sun, not just in summer.
A UV-inhibiting protectant on the dash, console, door cards and vinyl. It replaces the sacrificial layer the factory stabilisers used to provide.
$35 sedan, $50 midsize SUV, $60 large vehicle, as an add-on to an interior detail.
Free. Pointing the windscreen away from the prevailing afternoon sun genuinely reduces total exposure over the years.
On a street where you have any choice at all, it is worth having.
Dust and grit on a dash are abrasive every time you wipe them, and grime holds moisture against the surface.
Regular gentle cleaning beats occasional aggressive cleaning.
$45 sedan or midsize, $65 large. Leather dries and cracks on the same clock as the dash, and the sun-facing seat top is where it starts.
Lowers peak cabin temperature, which slows the outgassing and the heat cycling that eventually splits the plastic.
A well-protected dashboard should look like new plastic: an even, low-sheen, slightly matte finish. It should not look wet.
The wet look is the single most persistent bad habit in interior detailing. Beyond the dust and outgassing problems, a glossy dash reflects the sky straight into the windscreen on a bright day, which is a genuine visibility problem people accept without noticing they have created it.
The right technique is thin and even, worked in, and any excess buffed off with a clean towel. A protectant is doing its job chemically, not visually — the UV inhibition is not proportional to how shiny it looks.
This is what the interior protection add-on does, at $25 on a sedan or midsize and $45 on a large SUV or truck. It is applied to the dash, console, door cards and vinyl as part of an interior detail, and it is one of the cheaper add-ons on the list against damage that cannot be undone.
And to be plain about the ranking: if you only do one thing, buy a sunshade. We sell an interior protection add-on and we will still tell you the sunshade matters more.
Most of San Francisco parks on the street, which is exactly the case where this add-on earns its money. A car that lives in a garage is already getting most of the benefit for free.
Tell us where the car parks and we will tell you whether it is worth the $35.
More short answers live on the FAQ.
The services this guide is about:
Back to the full guide library.
We sell the protectant and we will still tell you the shade matters more.