Wow yeah, just got finished messing around with my room mates vanilla copy in SP, just driving around causing mayhem. Game is still an amazing blast to play, despite the blurriness. One thing I found in my quest to "fix" said blurriness was, of all things, to turn up the Brightness & Contrast (in-game) up 3 or so notches. Looked MUCH better.
And no, the "flicker filter" that someone will probably mention is not included in the display tab in-game when you're playing in HD.