I have DEPO Euros with american wipers and they work fine. True that there is a mount issue on the passenger side. I simple did not put in the last bolt. But the wipers do clear properly. Ideally Euro wipers are best and look better anyway.

As for the dim issue. Headlights take a lot of juice. So it could be that now that you have lots of new lamps up there, its easier to see a power issue. Such as a regulator going south. Which is easy to replace and not terribly expensive. With everything on, check voltage. Or do as I did, turn EVERYTHING on. ALL the heated seats, heated rear window, etc. The car at idle should be able to power it all. If not, the seats or rear defrost may kick out - indicated by the switch blinking. When there is enough power, the system will engage as normal.

You may want to also just check and clean all connectors. On the passenger side there are a few connections. I removed the nuts and used a Dremel with wire brush tip to clean everything. Made a big difference! Also installed a new ground strap from alternator to body.

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1991 560 SEL / 185k miles
1992 750il / 17k miles - project car