Unknown criminals in Spain have had the biggest impact on the pre-electoral battle in Germany so far.
This was not the result of a clever ploy by strategists from the conservative or the liberal parties. Nor was it the masterplan of the Greens or the left-wing Die Linke.
The big surprise was the revelation that Social Democrat Health Minister Ulla Schmidt had taken her official government limousine and chauffeur on holiday to Spain.
The SDP later decided to omit Ulla Schmidt from their election campaign, even though she was in theory entitled to use the car and chauffeur for both official business and personal trips.
But morally, Germans broadly believe it was inappropriate for the minister to fly to Spain while separately sending a Mercedes 5,000 kilometres south and keeping the driver on duty for two weeks, which were paid as overtime.
Moreover, Schmidt failed to convince anyone that the two official appointments she had in Spain during her holiday – which were apparently of limited importance - served as an excuse for using the official car.
Newspapers dubbed Schmidt 'S-Class Ulla' after the Mercedes model that disappeared in Spain. The news came as an embarrassment for the Social Democrats, who were busy portraying themselves as the better choice to lead the country out of the economic and financial crisis.
With less than two months to go before the elections, the SPD is credited with as little as 23% of the predicted vote in recent opinion polls.
For its part, the conservative CDU/CSU is steaming ahead, with 38%. The liberal FDP is polling at 13%, while the Greens are credited with 12% and the left-wing 'Die Linke' 9%.
Another problem for the SDP is that their leader, Frank-Walter Steinmeier, has low approval ratings as a potential chancellor – only 17% think he is capable of governing the nation, according to opinion polls. The same poll credits Angela Merkel with 58% to stay on as chancellor.
If these figures are confirmed in the September elections, the conservatives and the liberals could in theory oust the socialists from the government and form a coalition of their own, as they would jointly hold 51% of the vote.
But most political observers are assuming that the Conservatives and Social Democrats would prefer to continue their cooperation and form a government for another four years.
Guttenberg: The CSU's rising star
Meanwhile, the SPD is anxiously witnessing the rise of a new conservative star: Karl-Theodor zu Guttenberg, the new and youthful federal minister for economic affairs.
At first, Guttenberg's lack of experience seemed to offer a perfect target for SPD attacks on the conservative coalition. Indeed, Guttenberg is just 37 years old, an aristocrat and a member of the very conservative Bavarian CSU party.
However, to the SPD's horror, Guttenberg became the most popular politician in the grand coalition within a few months, even overtaking Chancellor Angela Merkel.
Guttenberg's bold positions on current issues – the financial crisis, the economic stimulus package and support for the Opel automotive group – won him praise for their straightforwardness, even if that led him to clash with other members of the government.
Since then, many political observers have been admiring his self-assuredness.
Far from offering them ammunition, the Guttenberg factor may thus represent a further disruption to the SPD's campaign strategy. Steinmeier had to immediately stop his aggressive political attacks on the young man.
Steinmeier wanted to open his electoral campaign ahead of time, so as to take Merkel's party by surprise. But it was he who had been taken by surprise by recent developments, analysts said.
In the meantime, the Spanish thieves, maybe assessing the extent of the damage they had caused, decided to return the car anonymously. But it may prove too late for the embattled SPD party.