To make sure that it wasn't just me or a brain addled by too much German exec exposure, over the past few months I've lent the car to three people for a two-day period, and then pooled opinion from those who also run Jaguars or have spent prolonged periods of time in them. That's an important distinction- I think many people struggle to understand modern car cabins on brief acquaintance because a human being just has to give its brain enough time to at least understand the logic system behind them. Assuming that there is in fact a logic system (original 7 Series iDrive, take a bow).
Everyone I have spoken to agrees that the Jag cabin isn't just old, it's illogical. The former isn't a crime, but needs rectifying soon. The latter is a problem because the touch-screen solution is at the heart of the problem.
Having so many functions paves the way for the clean fascia design, but it also means that changing tune and then reducing the effects of the bum-warmers takes too much time, concentration and irritation. Why my iPhone won't play a song for more than 90 seconds when the Bluetooth connection with the car's telephone is live I will never be able to explain or rectify. It is supremely annoying.
I've touched on this before, so won't labour the point much further, but in every aspect of its electronic behavior - in each system supposed to stand out on the spec sheet or make occupants' lives a little easier - the Jag feels unfinished.
Supporters with inside knowledge have sent me notes saying that the company did an amazing job with the XF and this facelift version with scant resources. Be that as it may, if you spend £50K on a saloon car, you expect the iPod thingy to work and the blindspot widget not to direct you into the path of fast moving vehicles. People don't extend sympathy for R&D budgets in the final reckoning.
This is a complicated relationship though, and it's soon to draw to a close. I defend criticism of the XF the way I do barbs aimed at family members - I can be rude as hell about it, but woe betide outsiders who try the same.
I love looking at it, I love the cabin's hearth-like glow at night, adore the ample performance and most of all I like the association of it and me. Funny thing that, but it's a key tenet of any car-human relationship. There are many cars I would love to drive, but just wouldn't feel comfortable doing so. The Jag works.
Fuel consumption has leveled to the 31mpg mark, which I find pretty unspectacular. A few days spent in a Panamera Diesel driven at similar speeds saw it hit 41mpg.
As for the harsh ride on start-up, I now have clearance to ask some probing questions to the people in charge at Jaguar. Knowing how little the tyres heat up after 10 minutes driving I'm pretty much convinced it's the dampers that need to rouse from slumber, but it'll be interesting to find out. It's such a shame because for me, and I'm sure many people, the first part of a morning drive is the best - with clear, interesting roads. In all cars I've become accustomed to extracting maximum fun from minimal throttle as the engine warms. In the XF you can't rev it and the suspension is closed for business.
So there is much to recommend the XF Diesel S, but the reality is quite harsh: the car is ready for replacement. It is based on the S-Type and it has done a fine job representing Jaguar in a tough sector, but for all its charm, it is now feeling dated.
Car: 2012 Jaguar XF Diesel S
Run by: Chris Harris
On fleet since: March 2012
List price new: £53,670 (base price £49,110 plus £1,275 for Adaptive Cruise Control with Intelligent Emergency Brake and active seat belts, £460 for Blind Spot Monitor, £240 for heated steering wheel, £700 for digital/analogue TV, £300 for DAB, £275 for heated windscreen with timer, £360 for 60/40 split/fold rear seats, £450 for JaguarVoice and £500 for front parking aid with visual indicator and reversing camera)
Last month at a glance: Niggles are getting more niggling and there's no escaping that the XF is feeling a bit left behind