How we research, and what we refuse to claim
We have not tested any of this. Here is exactly what we do instead, how the scoring works, where every number comes from, and what happens when we get something wrong.
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1. What we actually do
We compile published specifications. For every product on this site, that means going to the manufacturer's own product page or owner's manual, recording what it states, and linking the source next to the figure.
Where a manufacturer does not publish a figure, the spec table says “Not published”. That is not a gap in our research — it is the maker declining to commit in writing, and it costs the product points in the scoring. Right now, across the whole ledger, 253 of 340 specification rows we went looking for are actually published.
A worked example
The clearest illustration is the parking-mode battery page. The question “does parking mode drain my battery” is asked constantly and answered almost entirely with reassurance. So:
- Find published current-draw figures for cameras in parking mode. They cluster around 0.25 to 0.35 A.
- Add the vehicle's own published parasitic draw, another 0.03 to 0.05 A.
- Take a realistic usable capacity — about 15 Ah out of a 50 Ah starter battery before cranking becomes doubtful.
- Divide. Then apply the published cold-weather derating and divide again.
That produces roughly 43 hours in mild weather and 17 at -18 C, with every input sourced and every step visible. Nobody needs a lab for it. They just need to do it.
2. What we do not do, and why we say so
We have not handled, fitted, mounted or used any product on this site. There is no test bench, no owned units, no test fleet, and no photographs of anything in our hands.
This is stated early and often, not as an apology but because it is the reason our numbers are checkable. A testing claim asks you to trust a process you cannot see. A published specification with a link asks you to go and look.
3. How picks are scored
Every ranked page runs through one fixed rubric, in one file, so a reader can re-derive any score from the specifications printed beside it. Five axes:
| Axis | Weight | What it reads |
|---|---|---|
| Heat headroom | 22% | The maker's published operating-temperature ceiling |
| Install effort | 24% | How the thing attaches: plug-in through to hardwire |
| Price against the ceiling | 24% | List price on the compile date, against a $150 buyer ceiling |
| Written commitment | 15% | Warranty length in months |
| Spec transparency | 15% | How many spec rows the maker actually publishes |
Why those five
- Heat headroom because a parked car runs 60 to 70 C inside and it is the most common reason an accessory dies in its first August. Only 6 of the 41 products in this ledger publish a ceiling at all, which is itself the finding.
- Install effort because this site's reader is fitting it themselves on a Saturday, and half an hour under a dashboard is a real cost rather than a footnote.
- Price against a ceiling rather than against the category, because the buyer has roughly $150 for one upgrade and a category-relative score would rank an expensive thing well for being slightly less expensive than another expensive thing.
- Warranty because it is the only promise in the whole listing a court would read.
- Spec transparency because a maker who publishes an operating range is asking to be checked and a maker who publishes nothing is asking to be trusted. We prefer the first, and this axis is how that preference becomes arithmetic.
The full working for every axis on every product is printed on the page, under a “the working behind the score” disclosure. If you disagree with a weight, the inputs are all there and you can re-run it.
4. Every ranked page names something to skip
Not as a rhetorical device. A roundup where every pick wins is an advertisement, and naming a skip is the cheapest credible trust signal available to a site that cannot claim testing.
Sometimes the skip is a product that is genuinely worse. Sometimes it is a good product that is wrong for the specific question the page is asking — a three-channel dash cam on a commuter page, a 67W charger for somebody who only owns phones. Both are useful, and both are stated in the pick's own words rather than buried.
5. How prices work
There are two completely separate price concepts on this site and keeping them apart is deliberate.
- The live price is what appears inside a buy button. It comes from a daily refresh against the retailer's API and nowhere else. If it is more than 48 hours old it disappears and the button reads “Check price”.
- The list price is what a maker listed on one stated date. It drives the price axis of the rubric and decides which products are eligible for a “under $100” page. It is always shown with its source and its date, and it never goes anywhere near a button.
6. What the compile date means
Every specification on this site was compiled on September 4, 2026, and that date is printed beside the working on every product. Manufacturers revise product pages, discontinue models and change warranty terms without announcing it, so a specification is a snapshot rather than a permanent fact.
If you find that a maker has changed a published figure since our compile date, that is a correction we want — the contact page is here.
7. When we get something wrong
A wrong specification is the worst thing that can happen on a site whose entire argument is that the numbers are checkable. So:
- Corrections get priority over anything else in the queue.
- Corrections are dated and visible on the page, not silently edited.
- If a correction changes a ranking, the ranking changes and the page says it did.
- Discontinued products stay on the site and are labeled discontinued. Removing them hides that we recommended something that no longer exists — this review is the standing example.
The full editorial policy is here.
8. How we make money
Affiliate commission. If you buy through a link here we earn a percentage, at no extra cost to you. There are no sponsored placements, no paid rankings and no free products — there are none to take, because nothing has been sent to us.
Commission does not decide the order of the picks, and the standing evidence for that is structural rather than a promise: every ranked page names something to skip, and the top pick on the floor mats page is a maker whose store earns us nothing at all. It is ranked first because it is the only maker in that category publishing a thickness and a hardness figure.