I'll chime in as I know a bit about this.
I too have a diesel and needed a new aux fan. I did a lot of research and came across these NRF fans. I discovered that the diesel variant has that ugly little airflow blocking box but the petrol version from the same brand does not! I even emailed NRF direct to ask why, but they didn't respond.
I spend a lot of time on drive2.com looking at all the russian builds and there are several examples on there where they have fitted the petrol version of the aux fan to the diesels. You only need to modify the plastic cowling slightly. Where we have the intercooler, you just need to trim a bit of plastic off to make it fit. Other than that, they are identical.
I actually bought the NRF petrol version aux fan ready to fit to my car this summer. I will need to trim some plastic off but it was significantly cheaper than the diesel version and from my research, fucntionally identical but without that extra control box!
The part numbers are as follows:
Diesel version - NRF 47217
Petrol version - NRF 47218
Hope this helps!
