Glen

It's the Hella Raintronic, which is sold as a kit but also as a factory
fitting in some VWs, BMWs, Mercedes etc. Saabs too, I bet.

It comprises a light-sensitive sensor which you stick to a swept portion of
your windshield close as possible to the mirror, some wiring and a relay
which replaces the VW wiper-control relay plugged into your fuseboard. You
then have to mess around a bit turning it on & off per instructions to get
it set, then just set it to on and leave it set on intermittent (ensure
your wipers are not connected in such a way as to be live when ignition is
off, or they'll come on in the middle of the night while you're asleep and
flatten the battery!).

If it begins to drizzle the wipers will automatically come on at a
long-interval intermittent rate; as the rain increases the interval will
shorten, until with proper rain the wipers will operate at normal "on"
speed. The slowest interval is 60 seconds, if I remember correctly. My
van's in storage, so I don't know when I'll be able to fit the unit and try
it out!

Prices are steep everywhere. Hella NZ isn't going to import them due to
this, but very kindly offered me one of the 2 sets brought in for
evaluation...for a mere equivalent of $350US! And the relay probably
wouldn't have been correct for the Caravelle.

Shortly after this, in June last year, I found that a Canadian outfit had
them on special. Normal price $340.00, special $272CD. Shipping to NZ
airmail $20CD. I bought one. Specify your vehicle. Contact PG Performance,
10845 - 148th St, Surrey, BC, Canada V3R 3Y2,
<www.pgperformance.com/accessories/wiper.htm>
or contact Melanie <pgperf@bc-alter.nrt>.

PG also has Bonrath 4-nozzle wiper jet kits which attach to the wiper arms.
Apparently truckies love these. I got one for $24CD. Keep your reservoir
topped-up!

Andrew