I would say to go w/ the Satun Vue. The reason behind saying this has to deal w/ the cost and the Vue has a better ride quality even though it is still made by GM. I have ridden in one and I loved it.
Americans traditionally preferred gasoline cars. We have not been subject to high fuel prices as Europeans have. Even at $3 per gallon, we are far below European prices. Throw in the noise and odor, and that is why diesels have not caught on. There were small diesels from VW until recently, but as others said, the US is just changing to low sulfur diesel, and car makers wanted to stop production of the older variety to get ready for the new fuel. MB might have an E-series diesel on the market, but that’s about it.
You are obviously just too young to remember how GM almost single handedly destroyed the US diesel car market. As a quick and dirty stopgap measure they converted the basic Chevy 350 block into a diesel. All those folks who wanted good fuel economy, but would not buy a foreign car, jumped on these. The engine was a disaster. Diesel cars in general have suffered from that image ever since. Now, to be fair, there were some other drawbacks to diesels at that time also, like the classic diesel clatter and soot. Modern diesel cars don’t have those issues, but US consumer memory is long and hard to overcome.
I think we have the technology to make a small to mid-sized SUV that gets decent mileage, we (as consumers and manufacturers) just lack the willpower to do it.
Look you like the 1999,2000 volvo S70 well there is also the volvo V70 that is the station wagon version of the S70 it comes with everything that the S70 has but it has more room. check is out on ebay it is cheap. it comes with cruise control sunroof automatic 5 speed transmission it is a dream.
if you really were serious with this complicated request, you’d get a minivan!
Yay, a wagon seeker. Unfortunately, people have chosen SUV’s over the very capable wagon in recent years. But what you are looking for is a 3 or 5 series BMW wagon. Here is why it meets your requirements.
3 Series
Good mileage: 25+ required, 30+ preferred (I average 25mpg on mixed/higher speed driving)
- 4 doors, can hold 4/5 adults + dog (dog in back, 4 comfortably with some compromise/smaller adults (i.e. not fat))
- Diesel preferred, then hybrid, then gas Gas only for now unfortunately, maybe wait a year for diesel options from BMW)
- Safety is key, lots of airbags, and if it’s an SUV, stability control is required. [(I believe this eliminates the Escape hybrid) 6+ airbags, stability standard
- ABS required - standard
- I have an aversion to SUVs. Nothing larger than a Saturn VUE/Ford Escape size. I’d rather walk than drive a Suburban. not an SUV!!
- Station wagons okay. Sedans not as much. Yay wagons
- I’m biased against Ford/GM/Chrysler, but willing to change, maybe. Go germany
- Automatic transmission (blame the wife). Auto available, as well as manual.
- Price: under $45k, closer to $30k is better. (well outfitted new for under 45k)
And comes standard with sunroof, with optional 4wd and heated (front and rear) seats. Also has animal divider incorperated into rear seat divider. And of course, is a joy to drive. Bought new has 4 years service and repairs included.
5 Series.
The newest one has a twin turbocharged 3 litre engine, which would probably combine out to a 23mpg average. has all of the above but a bit more room for adults in the rear seats. New pushes 54k dollars, but a used one with a different engine (3 litre naturally aspirated) can be had for the upper limits of your price range.
Mercedes should be coming out with its C-class wagon soon(not available yet), and should have a diesel option to push it well into the 30-40mpg range. Mini Clubman will be small for you, but can hold 4 adults reasonably well, gets 23-29mpg, but only has 3.5 doors or something strange. Passat wagon would work as well, not a fan of VW though. Saab also makes turbo gas station wagons. 9-5 wagon would meet most all of your requirements, and gets 18/26mpg.
Thats all I’ve got, just stay away from the darn SUV’s and pray for more diesel options to make it our way, I am. Good luck.
The 2009 Honda Accord Diesel should be out before December 2008. But it sounds like you prefer a wagon.
Another nifty choice supposedly coming in one - two years, a Subaru Legacy/Outback diesel. Its an AWD wagon/sedan that gets 40MPG, I think it will be a hit given no competitor out there.
Audi A4 Avant is nice, although I think its just a dressed up Passat.
if you really were serious with this complicated request, you’d get a minivan!
But a minivan is NOT cool, gotta be cool ya know. 
I have a friend who drives a TDI Golf . . it gets great MPG and seats 5 . . put the dog on your lap if you feel you have to take it along. My dog likes the car but gets bored after a few miles, so maybe you can leave the dog at home. The other suggestions about the new diesels coming on the market makes a lot of sense. I’ve read about new VWs and a Honda diesel. Good luck! Rocketman
will someone tell me what “cool” has to do with selecting a car? What’s cool today may not be cool next year, and you are not buying a car for only one year.
It’s a stigmata with younger people that a minivan is something their (grand)parents drive, therefore it’s not cool/trendy to have one. Despite their versatility, they’re seen as evil things and it’s a last resort to get one. Some people would rather try and cram 3 large car seats into the back of a Corolla than have a minivan. as the OP stated:
I can’t do it. Call it religion or something maybe. I’m only 30 and I just can’t do it. Well, if I put a “If this van’s a-rockin” sticker on it…
I’m only 27, and the first thing I’d go looking for if I had kid(s) on the way would be a minivan
SATURN VUE. . .did you test drive the hybrid version? It’s a decent vehicle for the price <30K. It has special wheels and sits a bit lower than a normal Vue. I was quite impressed.
Get a Sprinter. It’s got a diesel and room for all your friends. And it’s funky enough that you just might like it. Just don’t try to park it in a garage - it’s too tall. No self-respecting soccer mom would drive a manly truck like that!
Oh, and it’s really a Benz, not a Dodge.