Yes, Germany benefitted hugely from southern European countries joining the Euro as it made it much easier for Germany to export goods to southern Europe.

At the same time it was made much easier (at lower interest rates) for southern European countries to borrow money from northern European countries and other markets, as creditors would feel more secure that they'd get their money back. Creditors would assume the northern European countries would bail-out southern European countries in case of problems.

And that caused southern European countries to lend more which might benefit a country like Germany again. These countries could lend more easily to buy luxury cars, for example.