How to read every chart in your report

We put charts at the centre of every report because a well-built visual reveals a trend that a wall of numbers buries. A column of figures can hide a slow decline or a single damning outlier; a good graph makes both jump off the page. This guide walks through each graph type you will meet so you can read it at a glance instead of squinting at axes.

The depreciation curve

The first chart most reports show is the value-over-time curve. The steep early section is the new-car premium burning off; the flatter tail is where value stabilises. Your car's position on that curve tells you which phase of depreciation you are buying into, and whether the worst of the drop is behind it or still ahead.

The shape of the curve also carries the Value Retention Index visually. A curve that stays high and flat is the same story the index tells in a number; reading them together is faster than reading either alone.

The price distribution band

This chart plots comparable listings as a distribution, with a shaded band for the typical range and a marker for the car you are viewing. A marker outside the band is the visual you want: left of centre is a relative bargain, right of centre asks for justification before you commit.

• Shaded band: the middle range where most fair prices fall.
• Centre line: the median ask for comparable vehicles.
• Vehicle marker: where this specific listing lands.
• Whiskers: the outer edge of plausible pricing.

A marker that sits far left is not automatically a win, either. A suspiciously low price often pairs with a thin history or an open flag elsewhere on the report, so the band is an invitation to investigate, not a green light on its own.

The mileage scatter

Here each dot is a comparable car plotted by age against mileage. The trend line is the expected accumulation; cars far below it are low-use, cars far above show heavy use. A point that sits oddly off the line is exactly the kind of anomaly worth a closer look, especially when it lands implausibly low for its age.

A chart's job is not to look impressive. It is to make the one fact that matters impossible to miss.

Reading bands, not points

The most common mistake is reading a single point as gospel. Our charts deliberately show spread, because the width of a band carries as much information as its centre. A tight band means a confident estimate; a wide one means proceed with questions rather than conclusions.

When a chart looks empty

Occasionally a chart shows only a handful of points or an unusually wide band. That is not a flaw, it is honesty: a rare model or a thin local market simply has less to compare against, and we would rather show you a sparse chart than fabricate a dense one.

Letting the charts ask the questions

The best use of a chart is not to confirm what you already decided but to surface the question you had not thought to ask. A marker sitting oddly low on the price band, a dot stranded off the mileage trend line, a depreciation curve steeper than its peers: each is the chart pointing at something the summary number alone would have smoothed over. Treat anything that looks out of place as a prompt to dig, not a detail to dismiss.

How the charts tie together

Every chart is built from the same underlying dataset as the score, so what you see visually and what the number says will never contradict each other. Read them as one story: the score is the headline, the charts are the evidence, and together they let you trust a verdict instead of taking it on faith.