[bluesti04]

I have been reading about the S4 for a little while now and I have decided to buy one for my daily driver. Right now I am driving an sti with 400whp and it will soon be more but I would like to just keep it in the garage instead of driving it everyday. I am just a little confused about the model years for the S4. For the S4 there is a 00' 01' 01.5' 02' no 03' and then 04' and 05'. I have read that it is best to not buy one unless it is atleast a 01.5'. Is this true and why is this? I have also read to change the turbos you have to take out the whole engine (I dont understand that)? Sorry for all the questions I just want to get this stuff straight before I go out and buy one. Thanks for any info.