I came across the same problem - bought a 99LS with just a SUB key, no master key. Then I bought a blank key with buttons on the head casing(3 buttons) on Ebay for $89 and had it cut by a locksmith who does sidewinder keys $65 ( he was reluctant to cut my blank key, wanted to sell me his own blank,but did it when I said he won`t be responsible if he messes up my blank key).Then I went to a dealer to get the new key programmed and ONLY THEN I found out that in order th program a master key, they have to get me a new ECU $1300, but said they will order the part for me for FREE!!! and I will have to pay just the labor. Later, when thr part came in, I paid $172 for installation of the new ECU and new key programming. That was GREAT!!!Thank you, LEXUS!!!