Opinion on Rx8

im looking to buy an rx8 and have found one that seems interesting. I have read around and learned a lot about rx8's but i am not anywhere close to knowing what to make of this. The rx8 in question is a 2004 gt with 100k km on it (about 60k miles) and it seems to be in good condition. the asking price is 500$ CAD. seems like a good buy but there were a few modifications done to it that worry me apart from the standard ones like suspension changes and regular maintenance. the original owner added a second oil reservoir to send oil straight to the apex seals so it does not steal any used oil from the engine... im not sure how it works but that was the explination of how it works that was given to me by the person selling it. secondly there is a midpipe instead of the regular catalizer and some sort of filter type thing to help keep the carbon from building in the engine. i think he called it a catchcan if im remembering correctly. any opinions on theses modifications before i go see it (and if i like it i will of course take it for a compression test).
thanks a lot in advance for any useful help :)