TurboTax will not support dual status returns.  You would need to find a tax accountant that handles dual status returns.

There is a way to use TurboTax for 2017 that would probably give you a better tax result.  You can file a 2017 full year resident return as married filing jointly (I assume that this is how you filed your 2016 return).  You would declare your worldwide income for the entire calendar year of 2017 including your German income after you returned to Germany in 2017.  Then you would utilize Form 1116, foreign tax credit, on the US return to offset any double taxation.  As German taxes are higher than the US, US tax on your German income (I would think) would be completely offset by your German tax either paid or accrued. No statement would need to be attached to your return when you file it as December 31 of the tax year is always considered by the IRS as the residency end date unless a statement is attached stating that you had a closer connection to a foreign country after the date you left the US. Please see attached Publication 519, Publication 519 US Tax Guide for Aliens.