Big question........

[rideon]

Don't get me wrong,this question is for all "Sunday tunners"
I know it's a big industry behind and a lot of people make a quick buck from this,but lately i end up tying to fix a car that is unfix-able by any other means,only to find out later that the car was tuned.
In some occasions,i sent the customer to 'unchip' their car and came back saying that it can't be done,and here comes my question:

Do you SAVE,or HAVE original files??,just in case.......