Cambodia-Laos by 4x4 car

[King of Jars]

Hi,

is Aranyaprathet legally open for cars?
Documents on hand are complete:
- blue Thai book
- ITP International Travel Permit
- Passport
- International Driving License
- all English Thai plates (introduced as a law on 11.6.2008 but nobody ever cared except in Vietnam)

I want to travel from Thailand via Cambodia to Southern Laos (Laos no problem) OR vice-versa. Anybody having any experience/hints?

Highly appreciated with thanks

Cheers
Peter