Juddz, like I mentioned in previous posts, there is practically no cost to return the system to factory. You keep your factory set up and then to return it, you can do one of 2 things. Have a muffler shop weld one bead to join the factory set up back together or do it yourself, using a exhaust pipe coupler. And as far as making it a bolt on, its not the mandrel bending that is costly it is the extra pipe and german style 3 bolt flange ( Mercedes doesn't use the common 3 bolt flange we us here in the US), not to mention my set up allows you to still use the factory hanger at the mid section for great support. The cost will go up another $150 to make the whole set up. I think my kits will be listing on EBAY for $100, with a reserve of about $175.