I would suggest you contact them and tell them when you bought it but just now put it on the car since you were building it. i wouldn't tell them it's been in service for 6 mos. because it obviuosly hasn't been. i assume you have proof of purchase, maybe even the original box it came in. I'm almost certain they will replace it for you, but you may have to pay shipping 1 way on the new one and they will give you a free shipping # to return the one you have. I would suggest you call them direct instead of trying to deal with the Ebay store, because a different person handles returns and and the Ebay store. Call and ask for tech or return service and tell them the problem. I can tell you they donot like bad press. It may take a little while to get the right person, but a 100.00 plus dollars makes it worth the effort.
Zip.