Rossing border Turkey - Iran without carnet de passage

[Degvr56]

Anyone experience(s) with crossing the border Turkey - Iran or Azerbaijan - Iran without the nessecity of a carnet de passage. We've read in some blogs ( not on this forum) about some embassies being helpfull with a warranty
Why no Carnet? The quarantee we've got to pay to the ADAC in Germany will only be returned when coming back to the homeland.
Our intention is to keep om travelling and don't like to sponsor the ADAC with several thousands of Euro's.