Re: 2nd ECU with a power tune?
Short answer, no. Your ECU has to be VIN coded for your car. However, if you choose to go with a Eurocharged tune you can buy the handheld programmer which you can have multiple tunes on and flash back and forth between tunes.
...can I ask, why you would want multiple tunes? Unless there is a specific ECU issue when you take it to the dealer, you will have no issue with the dealer...and if you do, prominent companies like Eurocharged offer free re-tunes.