No particle is needed after temporal nouns that is relative to the time where you are, like 昨日, 今日, 明日, 先週, 今月, 来年,,,. The particle に is needed for temporal nouns of absolute dates.
e.g.
母は12月に車を売ります。
The ~たい form basically can't be used for third person.
カーラは彼女の車を売りたがっています。