nsx-tech, I'm not judging the dealership on their business model. All I'm saying is that if you go do this aftermarket type of install at a dealership, you will likely be ripped off (relative to doing it elsewhere). I can certainly understand why the dealership may not want to do this type of install, but I don't understand why they want to charge a higher than normal rate or not warrant their work. If it's to dissuade the customer because in their experience they get the short end of the stick, then they can simply have a "no aftermarket install" policy, and be done with it.
On the other hand if they're willing to do the work, then I don't think that asking them to warrant their install is unreasonable. If the dealership screws up the install due to negligence, why should the customer be stuck with that, especially when there are plenty of other places that will warrant their work?
Similarly, the dealership usually already has a 'premium' rate for working on NSX's. Why should they jack this up another 30%? If they consistently find they are putting in more hours than quoted than they need to re-evaluate how they determine the time required for the install rather than just jacking up the rates.
Again, in the end if the dealership does not feel it makes business sense to do third party installs, they should simply refuse to do it. On the other hand, if they do give a quote on the job, then they should be prepared to be compared to other installers.