Know Your MOT

MOT failure rate and common problems for the Mercedes-Benz Sl320, and how to check your own car by registration.

Updated 05 September 2026.

6.8%fail rate

Mercedes-Benz Sl320 MOT failure rate

What a Mercedes-Benz Sl320 fails its MOT on, and the part that fixes each.

What it fails on, and why

Seat belts20.0% of failures

Seat-belt failures are frays, cuts, corroded anchorages, or a belt that will not lock under a sharp pull or retract properly.

Suspension20.0% of failures

Suspension failures usually mean a worn or snapped coil spring, a leaking shock absorber, or play in a lower arm ball joint or bush. The tester checks for corrosion, fractures and excessive movement. A broken front spring is one of the most common failures on higher-mileage cars and is a straightforward replacement.

Visibility/wipers20.0% of failures

Visibility failures include torn or smearing wiper blades, a washer jet that does not reach the screen, and chips or cracks in the driver's swept area. Blades and washer fluid are quick, cheap fixes.

The parts that fix each

If your car has just failed, you have 10 working days to fix the items and get a free partial retest. Confirm the exact fitment against your registration or VIN before buying.

For the seat belts failure: Mercedes-Benz Sl320 seat beltsShop Mercedes-Benz Sl320 seat belts on AmazonaffiliateFind Mercedes-Benz Sl320 seat belts on eBayaffiliate
For the suspension failure: Mercedes-Benz Sl320 suspension springs and shock absorbersShop Mercedes-Benz Sl320 suspension springs and shock absorbers on AmazonaffiliateFind Mercedes-Benz Sl320 suspension springs and shock absorbers on eBayaffiliate
For the visibility/wipers failure: Mercedes-Benz Sl320 wiper bladesShop Mercedes-Benz Sl320 wiper blades on AmazonaffiliateFind Mercedes-Benz Sl320 wiper blades on eBayaffiliate

Other models

All Mercedes-Benz models MOT failure rates comparedRanked worst to bestMercedes-Benz C-Class MOT failures22.4% failure rateMercedes-Benz E-Class MOT failures20.5% failure rateFord Fiesta MOT failures27.1% failure rate

Questions and answers

What is the MOT failure rate of the Mercedes-Benz Sl320?

It fails 6.8% of its MOT tests across the DVSA record, from 74 tests.

What do these cars fail their MOT on most?

The most common failure area is seat belts, at 20.0% of this model's failures.