A few people have been scammed on the site, Only use paypal to pay for items for sale by other members. If they will not use paypal, its likely a scam NEVER SEND E-TRANSFERS OF ANY KIND.
I think the difference between the 48 and 52 hp is just a restriction in the air box to get it to be below 35kW, which is a different category in Europe.
Went ahead with this mod over the weekend with AliExpress polarizing film and the results are basically the same.
Some advice and notes to add though: Try to be outside when you determine the film orientation that gives you your ideal contrast. I did mine indoors and went a couple of degrees...
Would you get a similar result with a regular polarizing film (non high-contrast)?
Shipping is very expensive to Europe, but the regular polarizing film can be had on AliExpress and the like for a lot cheaper.