CPO. You really need to read the fine print in any service contract. A dealer we bought a 2015 from tried to sell me a "service contract" that in the fine print protected against the exact same things that the Acura CPO warranty already covered. I asked for the factory CPO extension, and almost had to get an attorney to get it resolved. The factory CPO is actually offered by the selling dealer, then Acura backs that up. There is also an extension available for a fee ONLY at the time of sale from the Acura dealer if the car meets some other requirements. While technically both CPO and Service contract are considered insurance contracts, the CPO is backed up by Acura/Honda. There is also a CPO warranty that some dealers sell after the sale. They do not have as extensive coverage as those available at the time of sale. Other than wear items, oil, brakes, etc., my MDX is covered bumper to bumper for 100,000 miles. Some feel that is a waste of money. I spent an extra $1800 for that coverage because I have no desire to spend $5K on electronics if something farts and the only way to fix it is to start replacing things to see if it goes away. Although I am a journeyman mechanic and automotive machinist by prior trade, I have no interest in buying thousands of dollars worth of test equipment that would be needed to troubleshoot electronic problems on the MDX. I am not speaking of the OBDC readers but rather the equipment used to program changes into the car etc. The $1800 I spent on a CPO extension insures that the problem belongs to Acura and not me. In my mind I paid them $1800 up front to fix anything that goes wrong until 100,000 miles excepting wear items. The CPO is also transferable if I sell the car. How many people can sell their car to a buyer and say - the manufacturer will cover you bumper to bumper under this warranty until 100,000 miles. I'll get my money back in the sale price if I ever sell the car. In fact, I had that on the 2014 that was totaled by a red light runner, and Acura refunded the unused portion of my $1800 which I then used on the 2015 that replaced it.