If you go to an auto parts store, you can buy windshield sealant. It's like a clear thinned out silicone sealer that gets in all the cracks and does not make a mess. I've used it a few times. It will buy you some time till you can do the seal job right.

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1979 240D Caledonia Green/cream gone
1982 240D stick Ivory/Palimino
1999 E300D White/grey