how are you buddy
if u do a search most of the IS models have been covered
please refer to it next time
1. 250X does not come with HID
2. 250 uses H11 bulbs
3. OEM tyre size for X is 225/18 and 255/18 45 profile i think or 40
4. Pads there are plenty most owners have complained dust so i suggest going after market Ferodo/DBA/ etc
5. Most owners seem to go to their dealers for me for simple service i just use my local mechanic that iv been going for over 10 years
but major stuff i go to chatswood lexus which i think has 1 of the best service