My car has 75k on the original wires as well... They seem fine, haven't had any problems with them. I think I will get a set of the 9MM Ford Motorsport wires though. As an added bonus, they'll look cool...

1999 Mystique LS V6 Alpine CDA-9807, Rear deck sub, Opt. TB, K&N RU-3530/MAF adaptor, custom heatshield, FSVT 17's, SCT 4-program chip, Eibach's/ST200's, Hella Fogs...