Sensors

Hi,

For measuring the "speed / velocity" of an average car, I need some high res sensors. I've figured out two ways,

1. The average wheel / vehicle speed sensors that i've come across (for one car) give 8 pulse per rotation. Is this the same in case of other car or is it better.
- If this value is the same (on an average), then is there any sensor that i can use which will give me around 100 - 200 pulses per rotation so that i could have a res of around 0.2 - 0.5 inch per pulse.
- Again i'm a bit "confused" as to how to get this "fitted" into the car, any suggestions
- And then again would this be a good option

2. If the car has an ABS system installed, i feel this could be used:
- can i tap one of it's sensors to check the speed? as the ABS sensor can detect upto 1500 rpm.
- If i cannot tap then is there any way that i can use the same ABS setup to get the information out of it? i.e. by communicating with the ABS ECU

Thanks