You have a few choices here, but all of them involve replacing the broken handles rather than trying to fix them. Your first option is to find one of the remaining Holden dealers out there and order genuine replacements. The second is to find a parts recycler (a wrecking yard as they were once known) and harvest a set of door handles from a wrecked Captiva.

The other option is to find an online seller with brand-new or second-hand replacements (lots of parts recyclers also have online stores). You can order them and have them delivered, usually within a few days if it’s an Australian-based seller. Just remember to specify the handles that incorporate the keyless-entry button.

Regardless of whether you use an additive, a car’s Diesel Particulate Filter (DPF) will still need to be cleaned (or regenerated) periodically as soot builds up in it. Short trips where the engine doesn’t get a chance to warm up properly, as well as extended periods of idling in traffic and stop-start running will all hasten this requirement.

In the case of the Captiva diesel, the best way to manually force a regeneration is to put aside an hour and go for a decent drive. The advice from Holden in the day was to travel at more than 50km/h and at more than 2000rpm (which may mean locking the car out of overdrive) for a minimum of 25 minutes. During this process, you should not allow the speed or revs to fall below those two figures which suggests finding a decent strip of freeway to carry out this process. You should also not turn off the engine at any point in this procedure.

The broad idea is to get the engine and exhaust hot enough for the filter to regenerate and clean itself. Experience suggests a couple of attempts may be needed to get this to happen as it should, and in fact, the car’s computer will give you several chances to produce the desired effect before the workshop beckons.

If, after 100km of this type of treatment, the DPF light on the dashboard hasn’t disappeared, the solution is a trip to a workshop to have the filter investigated and, potentially, hand-cleaned. Also, a mechanic can initiate a DPF regeneration via a scanning tool.

Noises are impossible to diagnose without actually hearing them. So you need to take the vehicle to a mechanic and get the car to produce the noise you’re reporting. That may involve leaving it overnight or otherwise reproducing the circumstances under which it misbehaves. Experienced mechanics can often tell whether a noise is important or just wear and tear, and act accordingly.

For the record, your mystery noise could be anything from a worn turbocharger, a sticking hydraulic lifter, piston slap, bearing knock or even something as weird as a loose baffle in the exhaust system. All these things can manifest as random and metallic noises, and they range from simple to catastrophic in magnitude.