This was in response to an email I sent in asking if it would be worth it to get the latest firmware update to the 8500 I got off eBay.
Thank you for your interest in our products and future updates, but at this time there is no need to send in your 8500 for any service. We would be able to update the firmware, but the update would not affect performance or range. Also if there is an issue with the detector and you end up needing it repaired(most ebay purchases do) then please ensure you have a factory installed serial number sticker on the bottom of the detector. Without that serial number we simply will not be able to repair the detector.
Again thank your for your interest in keeping with the latest updates, and please enjoy the driving!