As 2 conquistas são secretas e não aparecem em lugar algum a não ser no site do game. Fui lá e transcrevo aqui as conquistas:
27. Paid and Displayed
Visit www.burnout.ea.com to find out more.
50. Criterion Fever
Catch Criterion Fever – Visit www.burnout.ea.com to find out more.
No site do Burnout:
27. Paid and Displayed (20 points)
There are 3 in Harbor Town, 4 in Palm Bay Heights and 4 in Downtown Paradise. Enter all 11 Car Parks to unlock this achievement. Whether you leave the way you came in, or jump from the top is up to you!
50. Criterion Fever (Xbox 360 only): Everyone at Criterion Games is infected with a virus. The virus is passed when those with it are taken down online, and from there it just spreads… You will unlock this achievement when you get infected.
Achei um tanto criativo a conquista da infecção. XD