YOU SAID:

Apparently he competed in GP2 in 2009 but we can't say we noticed.

INTO JAPANESE

どうやら彼は2009年にGP2に出場したようですが、気づいたとは言えません。

BACK INTO ENGLISH

Apparently he appeared in GP2 in 2009, but he did not notice.

INTO JAPANESE

どうやら彼は2009年にGP2に登場したが、彼は気づかなかった。

BACK INTO ENGLISH

Apparently he appeared in GP2 in 2009, but he did not notice.