Had to turn in the Red 2LT on 21 July as the residual on the lease was over $14k @ 31k miles. (+ no DCFC) Wife & I had decided on a White 2LT to replace the departed Red Spark.
We had stopped by our local EV-only dealer (Greg Platt @ Platt Auto Group) in mid-July to tell him what we were after and were willing to pay (under 24k miles & no more than $9k). Left our contact info & he said he'd call if he came across anything that fit our profile. Called him last Friday afternoon as I was getting tired of walking to the bus stop to get to / from work. He said the timing was perfect - they had just finished unloading a load of Sparks from the transporter about 90 minutes ago, was finishing up the paperwork to get them into his inventory system before giving us a call.
He told us to come on down that evening as he'd be there late. They had 5 2015 Sparks & 3 of those were white. Mileage on the 3 were 10K, 22k and 23k. We ruled out the one w/ 23k as it was apparent the previous owner had spilled a mocha or hot chocolate into the driver's side front speaker (Greg said the cars had only been cleaned up for the dealer auction - they still had the sticker on the windows - he hadn't had a chance to send them out for final detailing).
We checked the battery on the two remaining white ones w/ OBD II & TorquePro.
10k miles was manufactured 06/2015 w/ battery capacity of 16.40kW
22k miles was manufactured 01/2015 w/ battery capacity of 15.53kW
The 10k vehicle was listed at $10.4k and the 22k vehicle was listed at $9.3k. I had our loan pre-approval letter in hand and offered $9k out the door and said we'd take the car as it sat - no need to do any additional detailing or prep work. He pondered that for a moment, said "Sure!" and we were on our way in 45 minutes. Added bonus was we felt the 22k car was in better, cleaner condition - obviously stored in a garage. The slightly lower capacity won't matter for us - we hardly ever get the battery SOC into the yellow range on any of the other vehicles.
The deal worked out to be ~$8.7k for the vehicle & $300 for title / tags / transfers.
GOM nominal range after overnight full charge is 82 miles @ 5.2mi/kW = battery capacity of 15.77 kW
Battery capacity calculation from the energy usage screen works out to = 16.13 kW
Need to borrow the OBD II again to see if capacity value changes at full SOC. I haven't heard of any methods to regain lost capacity - once it's gone, it's gone.