wheel lug pattern size
Not sure about the IS's from 98, but most of the bolt patterns don't change for these cars. The ones from 2000 onward carry the following specs. Bolt pattern- 5X114.3,, Lugnut dimensions 12mmX1.5,,, and Hub diameter of 60.1 mm. Alot of your Lexus related questions can be answered by visiting WWW.CLUBLEXUS.COM. Go to the community selection, then forums, and have fun. This is aa Lexus enthusiast site in which there are many very helpful members there and can answer just about any Lexus related question you may have. Tell em TRUKN1 , from the LS forum, sent ya.