I do understand the issue. Seidio is selling a product that cannot be accurately measured by the firmware in the Droid. To answer the statement above, I would absolutely blame the car battery maker if it constantly read that it was on empty and I had to stop/restart the car to get an accurate reader. Not to mention, the argument about blaming the car maker if you have a broken meter doesn't work, because in this case, the meter is working exactly as it's designed. They made this extended battery with the advance knowledge of how the meter is designed...it's the same on all Droids.
If you are going to sell a product that you claim works perfectly with a phone, it should actually do so...or at the very least, you should be honest on your website. Let the consumer decide if they are willing to deal with never knowing if their battery is going to die or not based on each restart of the phone. It's a shady business model and absolutely underhanded on their part.
If they would have stated the limitations on their website (which I reviewed extensively), I would have absolutely no problem with the company.
I've bought extended batteries for every cell phone I've owned, and something like this has never been an issue. Motorola firmware limitations or not, Seidio should either disclose their products limitations or not release the product in the first place. I would even be happy if they have a software product available that would measure their batteries accurately.