My 1999 RX has 232K on it. I have bought the metal lines for the transmission fluid cooler lines, which I am having my mechanic replace. Prudence dictates that he replace the flexible hoses at the same time. Can someone estimate for me the total length that will be needed so that I can buy it? Thanks.

from the pics posted in the DIY thread , it looks like approximately 4 feet max should more than suffice. Autozone sells transmission cooler hose by the foot pretty cheap ($1.50 per their site) . Bring your replacement cooler lines and they should find the best inner diameter hose to fit.