As above 👍
However, when it comes to rejection over this issue, "difficult" takes on a new and subtly different meaning. Over 700,000 D8 cars have now been built with the faulty exhaust plus a good proportion out of 536,000 other affected models built since September 2015 are 3.0L diesels covered by JLRP00100
(source = JLR sales figures) available for download at
https://www.jaguarlandrover.com/2016/reports-and-financial-downloads . We don't know how many 16MY and later 3.0L diesels there are, but it doesn't really matter - the publicly available figures show that at least 800,000 vehicles - possibly over a million - are affected. That's the 5 models described by JLRP00100, plus the E-pace. A lot is at stake here.
Theoretically, therefore, any one out of 800,000 owners with a faulty diesel exhaust could sue JLR at the point when they refuse to accept a rejection made on the basis of "not as described" or "not of satisfactory quality". It would be expensive to start with but, based on what is now known about this issue, technical expert witnesses would have no difficulty showing that, on the balance of probabilities (the civil level of proof required in England and Wales), JLR sold the vehicle knowing full well that it wouldn't make the nominal service intervals due to documented engineering deficiencies. The consequences to JLR of losing just one case would include the triggering of an immediate avalanche of me-too claimants coming forward and the company could then be driven into a corner from which it might not be able to emerge: a group legal action (class action) is therefore not too difficult to imagine. But JLR would never allow that to happen, provided that the rejections keep coming at it just one at a time. The flip side should be that a real and determined threat to take the matter to court will always be successful before the hearing, otherwise they would be rolling the dice on a bet that the manufacturer literally couldn't afford to lose. No one who has threatened legal action has had any difficuly getting their money back from what we've seen.
If you go the other way and try arguing your case with them or the supplying dealership, then appealing to the motor ombudsman when they refuse to concede ground or taking the matter to the financial ombudsman for Black Horse / JLR Financial Services, they'll quite happily take you over the hurdles for up to a year or more. You might win in the end or you might not. Sometimes, they will just use the extended process to waste time or wear down the owner in the expectation that a significant proportion will just give up (read townandcountry posts passim). But JLR doesn't care one iota because, even when the case is found for the claimant a) the manufacturer is never named as the defendant and b) there's no system of precedent, so one successful case has no impact on any other.
Unfortunately, received wisdom and common sense repeated endlessly on an anonymous forum like this has no legal standing.
The bottom line is that to them this is just business. Expecting them to 'play fair' is like, well - let's just say that you would have a better chance with the tooth fairy.