Um, well, not to be mean, but did you read the manual? It should give information on the TPM system.
The TPM system and run flat tires are seperate. You do not need to purchase run flats.
Just as an FYI, you can get away with no sensor for now if you wanted, but in 2008 or 2009, you must have them. They will be mandatory on every vehicle.
Good luck!

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