Hi All!
Acting in the role of adjudicator, I looked at this many ways, trying my hardest to be fair to all contestants and these two closest guesses.
Finally, I figured the nearest "miss" should get the prize.
Matt, your odometer reads 2450.
Mac's guess is 2863. 2863-2450= "missed" by 413 on the high side.
AndyE's guess is 2135. 2450-2135= "missed" by 315 on the low side.
Therefore, the "closest" guess or "nearest miss" is 315 vs 413, so I declare AndyE "winner" in this contest.
All the best,
Dan. (...who is astonished the average of the two closest guesses is almost the exact distance Matt traveled).