Anyone else having trouble with some achievements?

Just finished a quick free play with the Venom GT on Old Mulsanne in an attempt to snag the “Record Breaker” achievement (Exceed 250 mph in any car), but it appears the achievement progress bar is stuck at 94% despite hitting in excess of 265 mph on the straight.

Another one I just realized I should have, but don’t, is the “Cover Car” achievement. Received my Ford GT about 10 hours ago, still nothing for the achievement. Perhaps I need to actually buy a GT in order to unlock it?

Any other achievements that are giving people trouble?