Can I apply for a TM30 online before arriving in Thailand?

Easy to do on TM30.io

If it's any help, I just went through all this in Phuket on a tourist Visa , I got a tm 30 from my hotel, went to immigration in Patong with my passport, 2 passport photos and the tm 30, paid 500baht and minutes later I had a residence certificate, went to the doctors and got a medical certificate for 100baht, my only problem was there was a 3 months waiting list at the DLT, so I paid an agent to organise an early appointment, 3 days later I had a Thai car licence, I think I had to pay about 300baht at the DLT for that licence and the next day I went in to do my bike licence, paid another 300baht and it was done and dusted, I arrived in Thailand on the 8th November, by the 20th November I had both licences, all done whilst on a tourist visa, so I am not sure about some of the feedback you are getting here, maybe its different in other provinces. Good luck.

I am in the process of getting car and bike licences in Kanchanaburi.

First for the certificate of residence, you will need 2, you have to get the TM30 + tabien baan and ID card copies signed from owner + 3 recent photos. 1 per cert and 1 kept by immigration. I paid B500 and it took about minutes to get them.

Next you have to go DLT

They want to see the certificate, a health certificate less than 1 month old, your passport with a long term visa, you need to copy the data page, visa, entry stamp. And your current full licence from your home country and current IDP (if you have one) and copy of licence

No an agent only does paperwork do it yourself

I suggest Motts agents for all your needs very professional.

As regards your driving license.. appointments at the DLT in CM are usually backed up and being booked around 3-weeks in advance.. meaning an online booking on 1-Aug will offer you an appointment around 22-25 Aug say.. so again time on your stamp is critical if you don't have an extended visa.. but you can drive on your overseas driving license for 3-months.. I'd suggest you get an International Permit or License from home country prior to travelling.. which will make your transition painless.. meaning 'less' pain not zero pain.. lol.. and again it's an inexpensive process so use of an agent is really unnecessary.. since you would have plenty of time to do this if you are in country continuously for 90-days.. when technically you would need to acquire a Thai license.. and i believe border runs would reset that clock anyway.. so perhaps there is no rush to do this?

You need to apply to Immigration for a letter confirming your address.. you can easily do this in person and you don't need an agent for this.. this is normally provided free of charge but in CM they charged me 500bht for said letter.. it will take 3-4 weeks to arrive and will be delivered by courier.. however it will only be valid for the period of your visa (ie. your stamp).. meaning if you enter on an exempt stamp it will expire when your stamp expires.. it is not an open ended 'confirmation' since the expectation is that you will leave Thailand once your visa expires.. but if you are staying in a private residence (eg. with Thai wife or family) and have applied for an extension (or another category of visa) you can then go to your local Amphur / Municipality to request a formal certificate of residence.. subject to your Thai wife (or relative) sponsoring you.. meaning they attend with you and certify that you are living with them.. I'm speaking from my personal experience having just jumped through all these hoops to further my married visa.. and whilst the process is a bit mind-numbing.. and definitely not designed for efficiency.. ie. you will have to bite your lip many times when evaluating some of the idiosyncrasies.. you can do it all yourself at minimal cost.. though it's not realistic to achieve all of this.. without extending your visa beyond 30-days.. hope that insight is helpful to you.

You may have a difficult time getting a Thai license. Like everything else in Thailand each office is different. They may require you to be on some sort of Non O visa before you can get one.

Your agent will take care of everything

A TM30 is instant if done online. There's no reason to do it ahead of time. It's notification of arriving somewhere, you can't do it early.