I am in a similar situation, but mine is going to arbitration through the attorney generals office, as Jaguar has not responded to my 3rd request for repurchase. They denied me twice, but only over the phone and email and never in a signed response outlining their reason why.
Our car is in the shop still today since July 16th. In total 79 days in shop since purchase March 11, and most of the 1540 miles spent driving 60 miles RT to the shop. They are replacing all the brakes today due to the squeal issue. I am curious how they were able to offer you a buy back. How many days in the shop? We had multiple issues as well, I posted some of them. They were playing games when I went to the BBB and would not reply to the mfg response form so I withdrew from that bogus process and went with a fair arbitration within the legal system in WA. It is required that we do one arbitration attempt to settle before going to Superior Court. I seriously doubt I will need to go beyond arbitration, but it will take time. I am hoping to simply have them repurchase, but if we are not fully settled prior to arbitration, I will continue with it to get some court leverage from a binding arbitration.
If I have to go to court to get full repurchase, I intend to get more than just a repurchase after this much abuse and free beta testing. I have an attorney in the que who has won 95% of the time in court. I do not hate JLR, but they need to recognize this is simply a Lemon and make it right.
To answer your question the tax credit is yours. You bought the car and that is all that is required. It is not transferable, and there is no time of ownership required. They wrote the tax law to prevent flipping the vehicles for the credit, but clearly you had no intent. This credit is yours to take, as no one else can against that VIN once it is sold. I might think Jaguar would try to argue a lower buy back due to your fortune, but that is not the case under the Lemon Law, you should receive the full amount you paid plus tax, and the insurance paid after the first repair attempt or after the first 15 days out of service. If you had leased the vehicle, they would keep the credit themselves as it does follow the original titled owner.