I keep on hearing a couple folks mention how ragingly inaccurate the DIC is. I've only ever used it in two cars and it's been deadly accurate in both. It's my belief that this is probably mostly only symptomatic of 97-2003 DICs. Frankly, it's amazing that it's as close as it is when its calculations are based on wheel speed sensors.
Keep us updated. I might have to make good friends with this seafoam fella.