TDA is "apparently" the advertising charge the mfr passes onto each dealer and is supposedly built into the invoice price the dealer pays the mfr. Dealers around here will show you their invoices with TDA on them but that really means nothing since the true invoice price a dealer pays the mfr is minus holdback and I'm sure they guard those sheets very very dearly, even internally. I hear TDA varies by region. In Chicago, its $325 per vehicle - used to be $250 around MY2000. Most dealers won't budge on it claiming the mfr charges it to them and they have to pass it on. I did buy one new Toyota without paying TDA, but there were some extenuating circumstances. If you work hard enough, you can get a dealer to drop TDA, but it's usually not worth it. Just wait for a rebate to roll around and eat it unless you're after a "slow mover".