I would not look for anything older than a 2010. I have an 08 and issues I am driven nuts by are as follows:
Tranny shifting - aweful. Some days norm, other days transmission won t shift till 3k and knocks u back from first to second. Embarrassing!
Backup cam and nav are slow and lacking behind fords or Hondas.
Also, elec issues are weird such as radio will remain stuck on a channel and set volume for 90 seconds before I regain control.
And know that if u buy an older e70 it may be due for a battery change
I believe after 2010 these issues were solved.
And the 4.8 is thirsty! I average 12.5 mised driving with a slightly aggressive demeanor.
Just my .02. Good luck!