The Porsche 928's engine is the least of it's problems. They are reliable as daily drivers, they grenade when subjected to track duty. This is due to oil starvation due to the poor oil cylinder head return to oil pan design. This problem often results in the failure of con rod bearings # 2 & #6.
https://www.youtube.com/watch?v=Wm1BlKelA3M
Beyond this, the vent control are vacuum operated and they leak, the AC evaporators fail and ... The cost of replacement Porsche parts makes these expensive to keep up with all things operating properly.
Cannot recommend the C-class Mercedes. A Realtor friend got a new one some years ago. The car died on a bridge causing a back-up, beyond this the car's ECU decided to lock her in the car. She had to call the tow truck with the tow truck trying to work it's way into traffic to rescue her. After this incident that was beyond upsetting, the C-class was towed directly to the dealer where she demanded they take it back where it was replace with an E-class that has been OK so far.
No experience with the Jag.
I like pre-GM SAABS, those built before 1999, specifically 9000 or 900 or just the 93 built in 1999. Anything beyond this is a NO.
With a growing family consider a hatch back or wagon as they can carry stuff, have equal performance to a sedan with next to no negatives.
Most consider acceleration and HP as performance metrics, ask yourself beyond the stop light grand prix where can one actually use 300+ Bhp & 300+ lb/ft 100% of driving time in real world road conditions.
It take much more than simple acceleration, techno widgets, and current market hype to make a pass to be considered a daily driver for me.
Do keep in mind, the newer the car, the more techno widgets it will have... that can go wrong that the typical owner cannot fix or diagnose.
My SAAB, 9000 turbo, 385,xxx miles and counting.
The SAAB, 9000 aero, 275,xxx miles and counting.
The 900se, 167,xxx miles and counting.
All are daily drivers. Pre-GM SAABs are design to be repaired and serviced to keep them on the road. They are not designed to be run totally problem free for 100,000 miles and be tossed due to the inability to service or carefully designed car that will all wear out when it's time...making the entire car disposable.
Why is odometer reading important? Cars can be completely wrecked in one day with less than a few hundred miles. Take it to an endurance race and drive the !!!! out of it, the abuse can easily wreck the oily bits. A car with 500,000 miles that has been very carefully cared for and it's condition well documented and very carefully maintained and not abuse while drive is going to be the better car if the car is designed to last and be serviced.
Bernice
Porsche 928 with a LS1 conversion (for reliability and easy to fix), but I don't need another project car either. Just to give some ideas of what I am realistically considering, two cars in the running are:
2003 Jaguar XJR
2005 Mercedez Benz C230 Kompressor
Both are under $10k
Just looking for some more ideas, as the only reason the Jag and the Mercedes are being considered is I have owned one of each in the past.