03 x5 vs any other year ?

[Easroc]

Am i missing something or is my X different in every aspect to all other years , most parts are interchangeable so i hear from 00 to 03, but the head lights aren't ,i have xenons i'd like to install halo's but that seem's difficult. I've recently purchased tailights ,that as advertised would fit from 00 to 05 on ebay ,only to find out they won't work cause my wiring harness has the pins different from the lights purchased .This has happened twice,so i returned the lights for a refund PITA , by the way lights were sonar
and advertised to be plug and play for the X5 from 00 to 05. Do i have one of those in bettween years that parts are hard to get ???