I have seen numerous convoys of Chinese cars heading into Thailand at Chiang Khong (typically 3-5 cars, sometimes up to 10 cars at once). This is not the best crossing as a ferry has to be used, which drives up the cost and time needed to cross (each vehicle is charged 1,000 Baht per way per crossing). All of this will soon change once the bridge opens later this month (apparently). Until then, why not consider driving further south to Huay Kon (near Hongsa) and crossing there? Sure the officials there may have never seen a Chinese car before but they would certainly allow you to cross and it wouldn't take more than a few mins being a very small crossing with little traffic.
@seahorse, I only have experience driving a Lao registered vehicle into neighboring countries, including Thailand and Vietnam, not Chinese registered (although I may also consider driving my new Chinese car into Laos and Thailand in the near future) but finding the place to get your exit stamp for your paperwork in Chiang Khong wasn't easy. It was easy enough to go to passport control, hand over my passport and get a stamp (and then get an exit stamp for my car passport from the nearby customs building), but another exit stamp, the same triangular one you get in your normal passport also has to be stamped into your car passport in addition to the normal customs stamp. Without it, the Lao officials will direct you back to Thailand to get it done there before stamping your documents on the Lao side.
Note that until the bridge in Huay Xai is completed, customs and passport control are located about 5km apart. Yes, this means your car documents will be examined at the port you enter with your car but in order to get your legal permission to stay in the form of an entry stamp/visa (if required) you'll need to drive almost 5km along the Mekong River road (turn right immediately after the customs house) and then search for immigration.
For all of these reasons I believe it is too frustrating to deal with the Chiang Khong/Huay Xai crossing as you'll probably spend the better part of 1-2 hours crossing in each direction and that's if you have all your stamps and documents in order. However, as mentioned this is likely to change very soon once the bridge opens, by which time everything can be done very quickly and smoothly like at all other Thai-Lao crossings I have been to.
As far as Chinese drivers licenses are concerned, they are technically valid for use in Laos or at least, the Lao authorities won't be able to read them anyway and will essentially turn a blind eye to their use. If you are caught for any driving offenses (rare, since police are a rarity on Lao roads though you may see some near Huay Xai and other built up areas) they are almost always more interested in some money than your license and if you can't speak Thai or Lao, communication will be very difficult anyway.
In Thailand, there is nothing official I have read that suggests that Chinese licenses are not valid for use there and although you would be driving your own car into Thailand, it would still be better to obtain an international license and/or use your national license from a developed country as Chinese licenses only have the front in English, while the reverse explaining vehicle types is only in Chinese. Based on my experience with car rental agencies and the police in Thailand, they are not particularly keen on recognizing licenses from countries such as China and Cambodia, although this won't prevent you from driving there on a Chinese license. At the customs checkpoint, nobody will be interested in your license or ask for one, the car is much more important.
Although this was not mentioned, my understanding is that Chinese cars are forbidden from crossing between Laos and Vietnam.