Ok, I am no mechanic, but I have a fantasy and I wonder if it were even possible. Can you take an old body, wagon of course, say from the 50s, 60s or 70s and replace all the mechanics, engine, transmission and so on with modern day parts, or even a hybrid wagon?
When I say modern parts, I do not mean replacement parts for the originals, I mean a whole new thing. Say, a Subaru all wheel drive system for the body of a '66 Catalina wagon. That sort of thing.
Your taxes at work prove it out all the time! http://www.evalbum.com/2093 The EPA funds some of those conversions. http://www.evalbum.com/2087 Just use the PREV/NEXT buttons to flip through. And this one gives you all the instructions: http://www.evadc.org/build_wiring.html There's also a movement to build solar steam-powered cars, especially in big wagons, because of the long roof and the stronger suspension for the storage cell. It's a heavy gaseous compound that can handle temps of up to 700F. Only works in sunny climates though. http://solarsteamtrain.com/cms/content/view/26/28/
Speaking of Hybrids... You can register (free) for MotherEarthNews emails and get all kinds of tips and DIY info on home projects and greenie stuff (I'm a big fan on saving money and testing my skills and skullbone). Today's project is converting a gas-powered garden tractor to electric! http://www.motherearthnews.com/Do-It-Yourself/Electric-Garden-Tractor.aspx You might like this too. It's an old 1980 article from MotherEarthNews, from another site - DIY Water Injection for under $10.00!: http://journeytoforever.org/biofuel_library/ethanol_motherearth/me3.html
This looks like a good hybrid modification. Mostly applicable to pickup trucks due to size but could be adapted to a wagon... <http://d.yimg.com/kq/groups/167923/1190203375/name/Thefastest57chevyintheworld.wmv>
Just about anything you can dream up can be done, with enough money, time, and skill - mostly the first one. Look at the hot rods done by Chip Foose, Troy Trepanier, et al - basically hand built vehicles with original or heavily modified bodies.
Once Krash gets to Oregon he'll install a 5.4 liter engine from a 500KR Mustang in his Focus. Just a little welding and a bit of cutting should do the trick.
Naw, that's not how you do it.... You take the whole 500KR Mustang, remove the body, and put the Focus wagon body on to replace it. Simple.