Just picked up a 75 914 and the previous owner deleted the heater and fresh air blower - i can live without the heater (racing exhaust) but obviously have a very major water issue with no fresh air fan and drain tubes etc...really dont need or want the fan and the prices are really high even on eBay - anyone every come up with a creative way to seal that area up and drain water away? was thinking about something flat and sealed up from underneath or fabricating a small box with drain tubes..Anyone else solve this? Thanks

I can supply you the blower box to bolt in place

No reason to make it harder than it has to be

For my race car I made this aluminum tray that screws onto the brackets below the cowl. I added some rubber edging to seal it against the underside of the cowl.
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Don't laugh but maybe a quick and fast way ...

Clear on top or black from underside..

https://www.flexsealproducts.com/product/flex-tape/

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not a bad idea....then i could saw it in half too and tape it back together...

Thanks for the suggestion