Car Stall problems of the 2003 Ford Thunderbird

I've owned my 2003 Thunderbird since it was new. It now has 65000 miles and is driven only 2000 miles a year, over the last 5 years. During this period, I have had all 8 coils replaced, one at a time. The first time was within the first 1000 miles. Generally it occurs while driving in traffic, being on the freeway or on local streets. The engine starts to misfire and not function. After the 3rd or so incident, I was informed that Ford recognized the problem and would honor the repair. The only problem with this, knowing of the problem, they refused to replace all at the same time. In other words, they would only replace when the coil malfunctioned, this now has occurred 8 times. Now my motor has failed and needs to be replaced. My understanding is that when the coil malfunctions the corresponding cylinder also is not functioning properly. Again, the car only has 65000 miles and has never been mistreated. The cost to replace the engine is almost $10,000. This motor is a Jaguar production 3. 9 model. Done when Ford had a brief relation with Jaguar. To say the least, I am very disappointed with Ford and their lack of taking responsibility. By the way, when they replace the motor, the old coils will be reinstalled on the rebuilt engine.