Good well looked after XJ-S's are okay.
The problem with any big car is as it get's cheaper things get missed and they don;t get serviced like they should do. My last one cost Â£1200 per year, with out anything going wrong, to keep running. But she never let me down!
Buy a really good one, look after it and don't use it as a daily driver and it's as reliable as any other luxury car.
I have half an eye on a 24000 mile 1980 V12 XJ-s right now. Really nice!
No room for bikes and I should build a garage first really!
EDIT: The last of the pre-HE XJ-S had Lucas P-Digital injection (sounds cleverer than it is) and no concern for emissions or consumption. They would AVERAGE 11mpg
However they were also the fastest road XJ-S's ever, including the TWR 6.0 Litre conversions.
Somerset, like 'Heartbeat' with newer cars!
Retro MTB: 1992 Cannondale 3.0 Deore XT M730. 1992 Marin Pine Mountain Deore DX M650.
Retro road: 1992 Eddy Merckx Corsa Extra Telekom Shimano 600 STI. 1993 Dyna Tech Ti.
Modern: 2006 Wilier scandium Ultegra 6600. 2014 Wilier GTR Ultegra 6800.