Hello, I was planning something similar before my trip and was also a little worried about hidden fees and deposits, as there are many agencies in London and reviews of them vary, I asked a few friends, and one of them gave me a good recommendation lamborghini hire London  a week ago, I rented a Lamborghini there for a few days. The booking process was simple, everything was clearly explained regarding insurance and deposits, and there were no unexpected additional costs, the car was delivered to the hotel, it was in good condition, and I got my deposit back without any questions. You can check out their options and terms and conditions. I really liked it.