Ford Repair: Mustand V8 - where does the oil go?, tail pipes, oil residue

Question
2003 GT V8 automatic. Clean tail pipes. No drips on the driveway. Loses 1/4 qt per 200 miles, carefully tested twice. Haven't put it on a lift for this because I just bought it and have until tomorrow to turn it in no questions, so maybe it's too late to ask. But it's a gorgeous one owner, 39000 miles. runs quiet, cranks and shuts off solid. I'd love to keep it, but where is the oil going? That's a little over 1-1/4 per 1000. A mechanic, detail shop and body shop all told me to keep it, but they didn't notice or know about the oil. I have until about 3PM eastern daylight tomorrow to decide. Thanks.

Answer
pull plugs look for oil residue-have leakdown test run if time-if one particular cylinder doesn't show residue more than another figure valve stem seals-a 5-6 hundred dollar repair-then change to a 100 percent synthetic oil like amsoil or mobile one extended-good luck.