In 2015 I was looking for a diesel 4WD to tow a 1500kg touring caravan and had never heard of an Antara. The trade reviews were not good but owners' reviews were not bad. I have been towing for 35+ years and this is the best towcar I have had. An SE Nav has more refinements than other models but nothing flash. The 2.2 diesel is meant to be better than the 2.0 and is chain driven, rather than a belt. It makes more noise as a consequence but I couldn't care less about that.
All cars of all makes have faults - some serious (in terms of expense). Having driven diesels for over 30 years the basics are:
use good quality fuel;
don't do short hops (e.g school and supermarket runs) - the engine never gets hot enough;
give it an Italian tune-up on the motorway every now and again;
change the anti-freeze and brake fluid every couple of years or so;
when an oil and filter change is done also check the diff, gearbox and transfer box fluids - very important;
look after the DPF (Diesel Particle Filter) - if previous owners have done short hops this is likely to be messed up, and expensive;
check on the recalls via Vauxhall UK - particularly starter motor cable issues, ignition switch and engine undertray;
earlier models were prone to an oil leak that was an 'engine out' job to cure properly;
transfer boxes on all AWD/4WD cars - no matter who made them - can fail if abused or neglected;
an Antara is not designed for off roading, so don't do it, but it is good for towing a trailer on wet grass;
read the OM from cover to cover - there is quite a bit of information within it.
Use the Search pages on this forum for a wealth of information concerning these under-rated vehicles, including spare wheel advice, parking brake use, etc. etc.. Also, there is another Antara forum - albeit much smaller - where similar issues are discussed if you have no luck here.
I have found Vauxhall UK and my local Vauxhall dealer to be most helpful in keeping this car in good condition. Don't be afraid to contact them.
2015 2.2 CDTi SENav 163ps manual 4x4 in Carbon Flash with 19\" alloy spare towing a Bailey Unicorn III Madrid @ 1500kg.