Personally I would reply
dear sirs,
I would like to move this situation forward by telling you to stick your Corvette where the sun doesn't shine, I signed up two years ago to purchase my dream car for the MSRP as stated at the time of order, you sir are just trying to profiteer out of my situation and the factories inability to produce enough cars for world wide demand, therfore I would like my deposit returned with two years worth of compensation added, I look forward to your response ......