I have not had a Jaguar for quite sometime but apparently the reliability have improved a lot. I am into my 3rd Audi, and the first (own from new for 4 years) did have electrical problems and broke down once 2 months after delivery. Second (owned for 3 years from new), reliable but still have some electronics issues which is annoying; 3rd, owned for 3 years from new, still running great and zero problem.
Yes, an Audi would be a more reliable automobile than a Jaguar, because Audis are famous for their reliability. Even the name Jaguar screams flash and power. It is true that the Jaguar has flash and power, but Audis last longer than Jaguars do, and they tend to have fewer lasting problems.
The Audi does not have the name recognition that a Jaguar has in the car market. The Jaguar is currently trying to change it's image as an unreliable car. They have always been known for prestige and power but not for staying out of the repair shop. The Audi while less prestigious is known more for its reliability.
When it comes to cars and reliability even the most expensive cars may not be the safest or most reliable. The Audi is an all around in my opinion the more reliable car. When you think of a Audi you think family, safety, comfort and style. On the other hand when you think of a Jaguar the first thing that comes to mind is speed and looks !
I have owned both types of vehicles, and have several friends who have also. The Jaguars tend to break down more often and require more maintenance than the Audis did. The Audis tended to perform better and last longer. Also, most folks had better luck with them in general than they did with Jags.
From my perception I would have to say when it comes to reliability the Audi and the Jaguar should be on par. Given the prices of those vehicles I wouldn't want to pay for either of them. I believe overspending on vehicles is a waste of money. You can buy a reliable vehicle for much less.