Hi, I realise that this is a couple of years on, but my i30 has exactly this door lock issue, only it's the front passenger side. Secondhand parts are cheap enough but my local garage won't fit these - they don't want to be liable if they go wrong. Therefore I'm considering giving it a go myself but would find the photos that AlanxB mentions really helpful - is there any chance of getting hold of these please?

For interest, a lock and door card from a breaker is £120 delivered. The lock alone from Hyundai is £272 and the door card £1199. That's not a typo. Of course there's always a risk that a secondhand part will fail sooner than you'd like.

By 'local garage', do you mean main Hyundai dealership or just the independent you use? The latter (a good quality one) should be more amenable in such circumstances (for 'older' cars well out of warranty, though you obviously want to avoid 'cowboy' outfits, and sometimes they aren't as easy to spot as some would have you believe.

I understand fully as I had a similar (expense) situation with my (then) 18yo Mazda3, where a lambda sensor (fitted cost at the dealer around £250 - £275, local indie about £180 - £200 if I recall [both using the same Denso sensor]) on the exhaust had failed, but because it we seized on, the whole exhaust manifold had to be replaced.

Total cost (the indie wasn't capable of this bigger job) at the main dealership - £1750. had to be done as the faulty sensor could've caused a emissions fail on the MOT. More than my car was worth at the time, but still cheaper than buying a replacement car that otherwise was reliable.

Older cars can be great until something goes wrong, especially if parts are hard to come by, or no common 'pattern' parts are available that can reasonably reduce the cost of the repair.

I agree that using second hand parts can be a risk, particularly if they are complex and/or moving ones, whether mechanically or electrically actuated. Not so bad for trim or bodywork whether you can reasonably tell its condition.

One of the problems with 'modern' cars is how much complex, inaccessible stuff goes into most of the parts, meaning a repair outfit cannot reasonably guarantee the fitted second-hand part will work - whether at all or reliably over a reasonable period.

You could end up having to have it fixed or replaced again (possibly with the expensive OEM part), maybe having to fix other problems the faulty part has caused, due to a hidden fault.

Things were easier when they were simple parts, manually actuated (like door mirrors) or they had more basic mechanical or electrical sub-components that could be quickly / easily tested and/or replaced as necessary.

Unfortunately, those days have been gone for two, maybe three decades for the most part. You never know, you might be lucky if you used another (reputable) outfit, but you can't always guarantee they will be good (reviews can obviously be faked, goo or bad), and the issue with the parts themselves still holds.

I'd probably only use (breaker's yard) second hand stuff for bodywork, seats, interior trim, etc where the you can more easily determine if it's in good condition.

Sometimes some car 'owners' clubs can help, though outside of performance makes and models, many are falling by the wayside these days, often because of the cost and time spent in keeping them (websites included - not 'free' as they might've been 10-20 years ago, not helped by users shunning increasing use of ads via blocking software) going, plus many people don't want to work on their own cars any more, often due to the issues I've mentioned (you can easily get into a right pickle if you're not a good home mechanic.