Audi A3 05 Undertray same as other models or VW?

[Ulook]

Hi. Iv been doing work on my wifes car and want to also replace the undertray as it is split and not worth putting back on.

I went to my local breakers but they had no A3s. Which got me thinking, since most of the parts in the engine bay are interchangeable on Audi, VW and skoda, would i be able to get an undertray from say an A4 or a Golf/Passat from the same generation and have it fit?

Thanks.