I had an opportunity to drive a 2006 Five Hundred for a couple of days... an SEL model with FWD and 6-speed auto. Red, like the one to the left.
Summary: a nice car... but one in need of a bit further further evolution.
Starting with the seats.. they were very poor. I look for a car that I can stand to sit in for more than a few hours... and this isn't it. There is very poor lumbar support - even when you find the (oddly located, for a Ford) lumbar control. And as is too often the case with too many Fords, the thigh support is too short. And as is always the case with Fords, the "leather" has more than a few too many of the qualities of vinyl.
I had hoped for better comfort here - especially given the Volvo roots of the car (it's a platform-mate). Despite the occasional well-intentioned attempt, Ford engineers rarely get seat support and long-term comfort right.
This is a tall car - when you get into it you realize that head room won't be a problem. It would probably fit a 6'6" person without any issues, and more if you lower the power seat.
The dash and doors are decorated with fake wood - typical for Ford. These are an option, but one which you will probably be stuck with on whatever model you want (like the fake woodgrain dash in an Explorer, or the giant chrome schnooz).
The Five Hundred is a big car (by current standards), although the driving dynamics are such that you really don't notice it except when pulling into/out of parking spaces. The steering ratio is good (15.8:1) and the turning circle is good - not extraordinary (39.7'). The car itself is 200.7" long and fairly wide at 74.5". As equipped, it weighs about 3700 pounds.
The 3 liter V-6 (203 horses) is "adaquate" - and is helped enormously by the 6-speed auto. It shifts well, and a bit quicker than most Fords (it could be better). There is no automanual shift arrangement. I find it odd that Ford engineers didn't use the new cams for this engine that work so well in the Fusion (221 horses, with no other changes). The car could certainly use the power. If and when (nothing is announced, although intent is well known) the 3.5 engine becomes standard or an option, it should be considered mandatory. Of course, the Yamaha/Volvo V-8 that is rumored would also be very nice - but at that point all wheel drive would be mandatory and Ford should also development a more sportingly-tuned suspension.
Speaking of which, I found I was able to corner at extra-legal "brisk" speeds without issue. The obvious weak point is the all-season tires, but the shock valving was very good. Reasonably flat cornering, assuredness. Giving it my favorite highspeed-lane-change-while-cornering test, I find the front shocks are well tuned and the car maintains the line to the limit of the tires. Nice job here on the above-average chassis dynamics... it's no Lincoln LS (which in a recent drive performed very nicely in this test) but it would easily be more than adaquate for an enthuiast type driver to live with as a commuter car. It'd also make a nice SHO replacement with a V-8 engine, it's definitely a stealth car.
And I'd like to see Ford keep it that way. The European-style grill (also employed very successfully on the current Mondeo) is a handsome "form follows function" type of grill. Not like the bizarre and overly-chromed Fusion grill... which certainly must block airflow. Same for the taillights - they make sense where the Fusion clear taillights ruin the other clean lines of the back end of the car - and look like they were added by a high-school kid with only a few bucks to spend. IMHO, the Fusion is ruined by these styling oddities and would be a very nice car otherwise.
Compare this car to the usual Hertz Taurus I end up with on business trips? No comparison - this is a *far* more sophisticated and well though thought-out car. The ergonomics are far better, you can live with this car on any business trip, and it will keep you out of trouble on unfamiliar roads and poor conditions.
Ford didn't initially offer a nav system for this car, even though the dash is designed for the standard Ford-sized double-DIN unit. They must have had a supply issue, or just ran out of time. And Ford should offer HIDs as an option for their safety advantages. Strangely, the Mercury Montego clone offers them. That must be the implementation of "up-market".
A good thing: the armrest in the elbow area is padded. I've got a bad case of "Ford elbow" from all the hard plastic armrests I've been stuck with over my many years of Ford ownership and I'm really tired of it. Medically, it's a nuisance. Another good thing: height-adjustable shoulder belts. The red mark on my neck from too many cheap Mustangs without this important feature is just starting to go away.
A bad thing: the trunk lid. It shuts "like a Ford" - sounding like it was slammed shut even when it wasn't (and it did take some effort to close it from it's very high raised position). Ford needs to better emulate Toyota/Lexus and Infiniti/Nissan here . They have invested in all the right hardware - shocks and all - but failed to tune it well. It makes the entire ownership experience poor. Aren't they sweating the details? On the other hand, the trunk was literally enormous and could swallow up anything you'd care to take for a weekend - even 4 race tires. Certainly a set of golf clubs and luggage. The truck floor was even lower than the bumper height and the opening was as low as possible given bumper laws.
In a couple of months we'll have the answer to the future powertrain choice question - at least on the new V-6. Hopefully, I'll get a chance to check out one of those in the fall or winter.
Additional Images:
SE model - no woodgrain.

SEL and upmarket models - woodgrain.

Trunk:
