The 2013 Pro4X is for sale by owner #2 with 95K miles and appears to be in good shape. Owner #1 on Carfax report shows 1st oil change after 4K miles, second oil change after 3.5K miles and 3rd oil change at 65K miles. Carfax obviously doesn't catch every service from every shop or oil changes done in the driveway. The first two low mile oil changes tell me Owner #1 knew what he was doing, taking great care of the car for the long term but then it's a mystery about those next 4 years with no records. The other "unusual" record is 40K miles were put on the car in a 10 month period during the 7 years of ownership. My concern is the possibility of many missed oil changes due to time interval or mileage interval that have planted the seeds for future valve and ring issues resulting in premature engine failure in the next 50K miles and I want at least 100K to 150K miles from this vehicle before the engine needs to be replaced. At the moment there are no obvious signs of oil getting past the rings. Are there any reliable methods to find out if this engine has major problems that are in the early stages that have not yet shown any symptoms? Is bore scoping or oil analysis worth doing or should I just move on and wait for the rig to be listed that has all the records, either hard copies or all on Carfax?