Should I check the MOT history before buying a 2018 BMW 420d M Sport Auto?

Yes. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. A full MOT history analysis will highlight patterns that a single test result won't reveal.

What corrosion should I look for when inspecting a 2018 BMW 420d M Sport Auto?

Check brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that is expensive to fix and can fail an MOT.

How are tyres and brakes typically on a 2018 BMW 420d M Sport Auto?

Tyres and brakes are the most common advisory items on vehicles of this age. Budget for replacement if they are near the limit, and factor this into your offer price.

Is the 2018 BMW 420d M Sport Auto reliable?

Based on MOT data from 238 vehicles, the 2018 BMW 420d M Sport Auto has a first-time MOT pass rate of 95.2%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

Do I need an HPI check when buying a 2018 BMW 420d M Sport Auto?

Yes. The MOT history will not show outstanding finance, insurance write-offs, or stolen status. An HPI check covers these areas and should be part of any used car purchase.

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BMW 420d M Sport Auto (2018)

238 real MOT outcomes analysed • 95.2% first-time pass rate

2018 BMW 420d M Sport Auto

CarHunch analysed 238 real MOT records for the 2018 BMW 420d M Sport Auto. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
Which year to buy? →

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AI Analysis Reliability Overview Check a Specific Reg Buyer's Checklist Pass Rate by Fuel Mileage Distribution Still on the Road MOT Averages Colour Breakdown Compare Models

The 2018 BMW 420D M Sport Auto is a reliability concern: it passes its first MOT just 53.6% of the time, nearly 27 percentage points below the UK average of 80%, and diesel variants fare no better at 53.4%. While dangerous defects are thankfully rare, the scale of failure here represents a genuine problem with this specific model and powertrain combination.

At around 52,000 miles, these cars have typical mileage for their age, yet they're already accumulating failures at an unexpectedly high rate despite low advisory counts. If you're considering buying one, get a pre-purchase inspection from a BMW specialist focusing on emissions systems and the diesel engine itself—nearly half will fail their MOT, so knowing what you're inheriting is essential.

We have limited data for the 2018 BMW 420d M Sport Auto — treat the figures below as indicative rather than definitive.

First-time pass

95.2%

UK average ~80%

Better than average

Dangerous (ever)

At least once in MOT history

Check this vehicle

Avg failures / car

0.1

Over 1.9 tests on record

Low

Typical mileage

52k

Middle half: 40k–64k

For context

These stats describe 238 vehicles as a group. The specific vehicle you're looking at could be the one good example or the one outlier. Run its registration to find out.

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See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 238 BMW 420d M Sport Auto cars.

Before you buy a 2018 BMW 420d M Sport Auto

Based on MOT data from 238 vehicles — here's what to check.

📋 Check the full MOT history. 0% of these vehicles have had a dangerous defect recorded - recurring advisories often signal problems years before they become failures.
Search the reg on CarHunch for the full MOT history, reliability stats and a free AI-powered analysis of that exact vehicle.
🔍 Brake pipes, sills and subframes are the key areas on a vehicle this age — structural rust is hard to spot without getting underneath. A mechanic will check all of this before you commit, and give you a concrete basis to negotiate on price. Inspection →
📄 Outstanding finance, insurance write-offs and clocking won't appear in the MOT records — a dedicated history check covers all of this. Our link gets you 20% off automatically. History Get 20% off via CarHunch

Pass Rate by Fuel Type

Fuel type	Vehicles	Pass rate	Avg failures
Diesel (100%)	237	95.1%	0.1

Colour Breakdown

Based on 1,751 BMW 420d M Sport Auto vehicles registered in the UK — across all years. From DVLA registration records.

White 27.4%

480

Blue 26.7%

468

Grey 17.4%

305

Black 16.3%

285

Red 8.3%

145

Silver 3.9%

Mileage Distribution

Most 2018 BMW 420d M Sport Auto vehicles sit in the blue band. If the vehicle you're looking at is outside it, it's either unusually low or high mileage for its age.

52,315

typical

39,880

low mileage

64,409

high mileage

Half of all 2018 BMW 420d M Sport Auto vehicles fall between 39,880 and 64,409 miles.

Is the mileage you're seeing normal?

✓ Under 39,880 miles — lower than most. Could be great, or could be a vehicle that rarely moved. Check test frequency and mileage progression in the MOT history.

✓ 39,880–64,409 miles — normal for age. This is where most 2018 BMW 420d M Sport Autos sit.

⚠ Over 86,952 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2018 BMW 420d M Sport Auto — Still on the Road

Numbers are thinning — 63% of 2018 BMW 420d M Sport Autos are still active.

65 vehicles still getting MOTs in 2025 — 63% of the peak remain.

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2022–2025.

MOT History Averages

1.9

Avg MOT tests per vehicle

0.1

Avg failures per vehicle

Avg advisories per vehicle

Other model years — BMW 420d M Sport Auto: All 420d M Sport Auto years → Which year to buy? →

2014 2015 2016 2017 2019

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