@bucko, well, you may find that it's not a good idea to drive to Lao in a Chinese car for the time being anyway because Chinese interests are being targeted by shadowy Hmong/Lao insurgents in Luang Prabang, Vientiane and Saisomboon provinces. Earlier this year, a Chinese SUV was shot at and two Chinese tourists inside killed. Just now a Chinese registered bus travelling from Kunming to Vientiane was shot at, injuring 6 and killing 1.
Chinese plates could make you a target anywhere south of Luang Prabang and north of Vang Vieng even if you're not Chinese yourself, but those blue plates with the one Chinese character stand out.
However, even if they are able to stop the shootings and bombings (yes there was also at least one bombing in Saisomboon) questions are being raised about all the Chinese cars entering Laos, particularly during peak periods like CNY.
Neighboring Thailand is putting a stop to them starting in the next few weeks by requiring advance permission through a Thai based travel agency or tour operator 10 business days before arrival, submission of travel itineraries, 3rd party insurance, a special plate that must be inside the vehicle at all times, traffic orientation for one hour and possibly a Thai temporary driver's licences for citizens of countries who don't possess a licence usable in Thailand(especially for Chinese who don't possess international drivers permits since China is not a signatory to the UN convention on international motor traffic). Apart from this, travel will be permitted only in the border province entered (for example Chiang Rai) with further travel permitted only with a Thai guide.
Convoys will require a guide and police escort, though it is unclear how many vehicles constitutes a convoy.
Motorhomes and motorcycles will be banned from Thai roads altogether, only cars and pickup trucks with no more than 9 seats and a GVM of max. 3500kg will be permitted to enter.
Although these rules will not apply in Laos, if Chinese vehicles keep entering Laos in ever increasing numbers the Lao may also impose some restrictions of their own, particularly since it's rather unfair that the Chinese don't allow Lao vehicles beyond Jinghong (except buses, which are permitted to travel up to Kunming), while the Chinese are allowed free reign to roam around Laos.
Another issue although I think you have given up on the driving to Thailand in one car part is that very soon, Thailand will tighten up the entry of foreign registered vehicles.
Chinese vehicles flooded into Thailand during the recent CNY and they caused lots of accidents, near accidents and plenty of congestion, meanwhile the paranoid and xenophobic Chinese government doesn't allow Thai vehicles to enter except on an expensive tour with guide, deposit of 50,000 Yuan etc.
The Thai government is rightfully putting a stop to freeloading Chinese tourists driving cars without paying anything, while their Thai counterparts, get faced with a host of barriers to drive up to China.
So, given the lack of an agreement between the two countries, the Thai Land Transport Department and related authorities will soon require all foreign vehicles (except from countries with which Thailand shares an existing agreement) to provide advance notice 10 business days before arrival, through a Thai travel agency to seek permission for the car to enter the country. An entry fee of 500 Baht, plus another 500 Baht for a special plate that needs to be visible in the car, itineraries and driver's licences need to be submitted. A one hour orientation on traffic rules will be required, and travel outside the border province will not be permitted unless accompanied by a Thai tour guide. Motorhomes and motorcycles will be banned altogether.
So it's going to be the end of the road for easy entry of Chinese vehicles into Thailand; not much different to Chinese regulations on the entry of foreign vehicles to China and I think the regulations couldn't come soon enough.
@lemon lover, the border crossing at Mae Sot/Myawady has always been controlled by the Myanmar government and since Aug 28, 2013 is an official crossing that allows entry/exit with passports and visas to/from Thailand for Thais, Burmese and third country nationals. The previous rule that only day permits were issued and visas weren't recognized is no longer applied. In fact, even though day trips are still possible without a visa, Thai authorities no longer permit them to visa-free travelers in order to prevent visa runners from abusing the Thai visa system. So most foreigners will be entering Myanmar with a visa (and why would anyone bother going to a dusty border town for a day anyway).
Also, while parts of the road between Myawady (opposite Mae Sot) and Kawkareik/Hpa-an used to be Karen rebel territory and off-limits, the main road and townships are firmly in government hands and safe to travel through, hence why travel through the area has been allowed since 2013 with one exception for about 5 days last year.
The Mae Hong Son border at Khun Yuam may soon be upgraded to international status, according to an article from the MMtimes from last year.
@Peter99, many foreigners have crossed the India/Myanmar border at Tamu/Moreh recently but a permit is still required.
In terms of Mu-se/Ruili being opened, well, if you check out the mmtimes.com website, there have been updates on this recently. Indications are that there are some internal issues on the Myanmar side including possible border demarcation that need to be resolved but more likely, they've been waiting for the new immigration complex to be completed and the new government to make a ruling on upgrading the crossing to international status. Some recent fighting in areas not too far from the main Mu-se to Lashio highway have probably also delayed matters further.
In any case, bringing a car across is a no-no, except for limited travel up to 10km from the border of Ruili registered vehicles. Occasionally I've seen other Chinese registrations in Mu-se, but for further travel beyond the border, advance permission and a guide is required.
In fact, last July 2 Chinese vehicles, one of which was a motorhome was spotted in Pyin Oo Lwin just north of Mandalay. However, they had a guide with them.
Thai and Malaysian tours regularly enter via Mae Sot, Phu Nam Ron in Kanchanaburi or occasionally Mae Sai, but again, they all have permission except for local travel in the border towns near the Thai/Myanmar border which doesn't require any special permission but is only for Thai cars.
@Alien, yes only for these nationals. For everyone else it's as easy as always and I would expect more visa free agreements to be signed between Laos and some major countries, mostly western countries and possibly even China eventually. Currently Swiss, Russians, Japanese, South Koreans, Luxembourg and ASEAN citizens can enter Laos visa free.