There was an issue with motor mounts at one time. That could be the cause of the engine shake at idle. Would be interesting to see if these were replaced. If they let you take it for a day, I'd drive it hard and leave the stereo off and listen and feel for every vibration and rattle. Take it over some rough roads and give it a real thorough test drive for 24 hours. Use every feature and make sure they all work. That is a big discount! I was offered about half that amount for a 2020 loaded that had 5000 miles on the odometer. My concern was if problems had been corrected, would any show up later? Being OCD about my vehicles, I was afraid that if anything went wrong I would begin to question my choice. But I think that if you wring it out for 24 hours and look into the history, your gut will tell you what to do. Best of luck, let us know how it goes!