There is a swedish outfit that makes these.  The heat exchanger is a heavy
piece of pipe with about 3 feet (or more) of tubing wound around.  You cut the
rad return hose (the big one) and clamp this thing in-line.  The tubing
is covered by plastic to hold in the heat better.

It also has a check valve so when the washer fluid boils in the exchanger
it causes the fluid to circulate back to the reservoir heating up 
the whole tank as you drive.

I bought the thing at a SAAB dealer in Knoxville TN, don't know of another
source, but it shouldn't be difficult to re-engineer.

Had one for years on my SAAB before I got rid of it.  Worked great - even good
for summer use, the hot fluid melts bug goo really well.

- Frank

 >Date: Wed, 3 May 95 19:02:15 CDT
 >Reply-To: vanagon@lenti.med.umn.edu
 >Originator: vanagon@lenti.med.umn.edu
 >From: Alistair Bell <ui775@freenet.victoria.bc.ca>
 >To: Multiple recipients of list <vanagon@lenti.med.umn.edu>
 >Subject: My windshield washer heater gizmo
 >
 >
 >As reported earlier, I had a 4" length of 1/4" copper tubing soldered to
 >the side of my rad. To this I connected the windshield washer line in an
 >effort to create an ice-destroying spray! Well, I completed all of the
 >connections last night and tried it out today...it doesn't work! the water
 >doesn't feel at all warm! I guess I should have used a longer bit of
 >copper tubing. Oh, well. I'll wait until next winter, maybe it'll have
 >some effect.
 >
 >Alistair, back to the drawing board
 >

============================================
Frank Terhaar-Yonkers	
High Performance Computing and Communications Research
MCNC
PO Box 12889	3021 Cornwallis Road
Research Triangle Park,  North Carolina  27709-2889
fty@mcnc.org   voice (919)248-1417   FAX (919)248-1455