windshield cleaners?

["Shahrol Halmi" <alfalist@xxxxxxxxx>]

What do you guys use to clean your windshields?  I have some blotches (they
appear right at the trailing edge of the wiper blades when in use - as the
water dries up, they disappear) - I'm thinking that they are road grime
(diesel fumes cause this?) but I can't seem to clean them off!

I've tried:
1.  Windshield foam cleaner (like a glass cleaner, no ammonia)
2.  bug and tar remover, and then dishwashing liquid
3.  Bon Ami (suggested by the folks in bimmer-digest)
4.  non-abrasive bathtub cleaning liquid

Nothing works!  (well, the Bon Ami sort of works a bit) - it's getting
annoying now that the monsoon is here in Malaysia.

Any ideas?

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