If Tourist to Thailand, go to AAA location in USA, and get a International Driver's Permit. Been traveling in Thailand 10 years, been asked for it twice at the numerous road blocks.
If arriving on Sunday, just arrive on 30 Day Visa Exempt, it may still be 45 days at the time of arrival. Near the end of your Visa Exempt, simply apply for a 30 day extension at the local immigration office, usually granted.
You can get a 30 day extension in Thailand. Thus you only need to leave and re-enter once. Yes, you get the full 60 Days on re-entry, just be sure to have paper copies of MEV, and hand it to immigration officer, and check you were stamped in for 60 Days.
You can go Visa Exempt good for 45 days, soon to be reduced back to 30 days. Or get an E-Visa or a Multiple Entry E-Visa, good for 60 Days. On any of these you can get a 30 days extension.