We have booked with Grayline - for about $90 per person - we get picked up at the hotel (HoJo's) - shuttle to Universal - leaves around 7 or 7.30 pm (they originally told me via e-mail) - although park does only close at 8pm that night. After that we get a night-time tour of LA (with a couple of stops in Hollywood). We could have gone straight back to hotel after the tour for about $10 pp less.
We have booked this in just over 2 weeks so I can let u know how it goes, if you like.