Results by brand: 25th to 30th

* What Car? Reliability Survey 2012 * Most and least reliable cars rated * Top 10 - and worst - in each category, too...

Results by brand: 25th to 30th

BMW 25th
Last year's position 21/35
Cars needing repair work 41%
Average repair cost 420
Best model X5 ('07-)
Worst model 7 Series ('01-'08)

BMW climbed two places in 2011, but drops five this year.

The latest X5 ('07-) is the most reliable model, with a failure rate of just 21%. The average repair bill of 407 is less welcome. The 7 Series ('01-'08) recorded the largest single warranty claim this year, at 10,120.

Audi 26th
Last year's position 24/35
Cars needing repair work 42%
Average repair cost 471
Best model TT ('06-)
Worst model A4 Cabriolet ('01-'05)

Another drop for Audi, because of high repair costs and a poor RI score.

The A4 Cabriolet ('01-'05) is the least reliable, with nearly 40% of its problems being electrical and costing an average of 532 to fix. The TT ('06-) is better, with a 25% failure rate and an RI score of 80.

Rover 27th=
Last year's position 22/35
Cars needing repair work 43%
Average repair cost 383
Best model 25 ('99-'05)
Worst model 75 ('99-'05)

Rover ceased production in 2005, but there are plenty on the used market to choose from. Despite its reasonable 33% failure rate, the 25 ('99-'05) gets an above-average RI score of 130, thanks to a high average repair cost of 389.

The 75 ('99-'05) fails 47% of the time.

Jaguar 27th=
Last year's position 25/35
Cars needing repair work 43%
Average repair cost 428
Best model 25 ('07-)
Worst model 75 ('03-'09)

Jaguar had been improving until 2011, when it fell to 25th from its previous 17th.

This year, it's fallen again. Its best model, the XF, has a failure rate of just 24% and the lowest average repair cost of any Jaguar at 267.

The X-type, last year's best Jag, drops behind the XK ('06-09), which posts a range-low fail rate of 22%.

Mercedes-Benz 29th
Last year's position 27/35
Cars needing repair work 45%
Average repair cost 474
Best model E-Class ('06-'09)
Worst model SL ('02-'12)

Mercedes-Benz has slipped down the table this year, despite good results from the E-Class ('06-'09) with an RI of 22 and a failure rate of 11%, and the B-Class (RI 66 and 21%).

It's bad news at the other end of the range, though, with the SL ('02-'12) and CL ('00-'07) standing as the two most unreliable cars in the whole survey.

MG 30th
Last year's position 29/35
Cars needing repair work 45%
Average repair cost 474
Best model ZR ('01-'05)
Worst model SL ('02-'05)

The stand-out figure for people considering a used MG is the rate at which their engines tend to run into trouble. The 28% figure for problems in this important area shows that not only do the engines go wrong more than any other parts of MG cars, but also more often than the engines of any other manufacturer.

The ZR hot hatch version of the Rover 25 supermini manages a relatively good failure rate of 35%, but the TF sports car fails more than half the time and will cost an average of 422 to put right.

Results by brand 31st to 36th >>

See also: JD Power Dealer Satisfaction Survey >>