2021 Audi A3 S Line Comp 45 E Sa — MOT failures & pass rate

Across 709 MOT tests analysed for the 2021 Audi A3 S Line Comp 45 E Sa, the most common recorded failure areas were tyres, suspension and lighting & signalling. Its pass rate of 90.7% was in line with the average for cars of a similar age (91.2%).

Pass rate

709

MOT tests analysed

9.3%

Fail rate

in line with

vs cars of similar age

3.5

Avg age at test (yrs)

How it compares

Fail rate for this model-year against the segment and national averages for cars of a similar age.

Top failure categories

Most common MOT failure areas — 2021 Audi A3 S Line Comp 45 E Sa
#	Category	% of tests affected	Tests
1	Tyres	7.3%	52
2	Suspension	1.1%	8
3	Lighting & signalling	0.6%	4
4	Seat belts & restraints	0.4%	3
5	Visibility	0.4%	3
6	Other defects	0.3%	2

Percentage of tests with at least one failure recorded in each category.

Most common specific failures

The exact components most often recorded as failures — more specific than the categories above.

Most frequently recorded failure items — 2021 Audi A3 S Line Comp 45 E Sa
#	Failure item	Times recorded
1	Shock absorbers	8
2	Tread depth	7
3	Headlamp aim	6
4	Registration plates	4
5	Washers	2
6	SRS malfunction indicator lamp	2

Top advisory categories

Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.

Most common MOT advisories — 2021 Audi A3 S Line Comp 45 E Sa
#	Category	% of tests with advisory	Tests
1	Tyres	27.6%	196
2	Brakes	9.0%	64
3	Other defects	6.8%	48
4	Visibility	3.8%	27
5	Suspension	3.5%	25
6	Road wheels	0.7%	5

Failure rate by mileage

Higher-mileage cars tend to fail more — often the most useful guide to real condition.

MOT fail rate by recorded mileage band.

Fail rate by recorded mileage — 2021 A3 S Line Comp 45 E Sa
Mileage band	Tests	Fail rate
0-30k	250	7.6%
30-60k	361	10.0%
60-90k	84	8.3%

Failure rate by age

How this model-year's MOT fail rate climbs as the cars get older.

Trend over time

Fail rate by dataset year — 2021 A3 S Line Comp 45 E Sa
Dataset year	Tests	Fail rate
2024	356	8.7%
2025	350	10.0%

What to check before buying a 2021 A3 S Line Comp 45 E Sa

Before buying a 2021 Audi A3 S Line Comp 45 E Sa, focus on the areas it most often fails on. Tyres accounted for 7.3% of tests for this year.

Tyres (7.3% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
Suspension (1.1% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
Lighting & signalling (0.6% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.

Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.

Frequently asked questions

How many 2021 Audi A3 S Line Comp 45 E Sas pass their MOT?

90.7% of the 709 2021 Audi A3 S Line Comp 45 E Sa MOT tests in this dataset passed — a 9.3% fail rate.

What is the most common MOT failure on a 2021 Audi A3 S Line Comp 45 E Sa?

Tyres, recorded in 7.3% of tests, followed by suspension (1.1%).

Does the 2021 A3 S Line Comp 45 E Sa get worse with mileage?

Its MOT fail rate rises from 7.6% in the 0-30k band to 8.3% in the 60-90k band.

Methodology & source. Based on 709 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.