turbo
tune
downpipe
exhaust
(and their various dependencies)

Song, those are the four basics that have the best ROI, for when you do get around to this performance project. Here's a fun read by our own BMDubya: Base V70 performance upgrade.

Many parts are NLA.

I've had occasional luck with Genuine Classic Parts (in Sweden). https://www.gcp.se/en

Otherwise, it's been eBay, and/or JB Weld (for plastic).