Are the header categories (Bank Details, Monatsrate...) intended to be sort-clickable? If not, then it's not really a comparison list, but a results display without any obvious sort functionality. This might help explain your high drop-off rate.
My eye was immediately drawn to the dropdown list of search filters but I quickly realized that those are just the baseline search parameters. Changing them will alter your results list but still won't provide you any way of comparing the results you get back to each other! And (noch schlimmer) since your drop-down selections are based on what you personally want from a car loan, changing those parameters is essentially saying that your customer wants something other than what she actually wants.
The success of this, or any UI depends upon its ability to anticipate and meet the user's needs. Consider the user we'll call, Frau Anke Wagenkauferin, a 28 year old computer programmer and first-time car buyer from Dortmund who made the selections on the screen below.
Her job pays OK but not great, so 16,000 Euros is her limit, and she'll want the full 60 months to pay it off. With only that much to spend, she hopes to get a nice used car.
How useful does she find this display? Nicht sehr. It shows a lot of results but doesn't tell her how they're sorted, only that they conform to her search filters, which she already knew. She might figure out that the main sort criteria is price: low/high, or she might not. She may know what those two percentage numbers on the right signify that is different from what the big orange price, or she may not. She may know the difference between a three and four-star bank when it comes to auto loans and how that might affect her exprerience, or she may not. Her not-extremely-bright cousin Rolf might not know that he shouldn't ask for a 50,000 Euro loan on a 15,900 Euro used car, because hey, more money is better, right? And you let him do it.
Overall, the problem with this site is the problem with most of what's called "UI/UX" today. Too much visual design and too little research and discovery make for a site that looks wonderful, gets lots of praise from bosses, but doesn't reveal its flaws until the customers start using it.