Not possible. LH is the only *A carrier where you can use UA SWUs.

If you rent cars frequently from Hertz or Avis then you can earn 500 miles per rental on SK Eurobonus. I have earned nearly 30k miles on this and some other random things in the past 18 months. You can upgrade any fare to C for 30k pts and to Y+ for 10k pts from and economy fare.