Well, I'm going to be the detractor on this one. I've used sanitizer for years to remove sap. And while all the replies above warning you about the damage that can be done have their merit, you have to put these warnings in perspective with regard to the volume and time necessary to actually incur the damage.
First of all, I have yet to use a product specifically formulated and sold as a tree sap remover that comes anywhere close to how fast sanitizer works at removing sap. That being the case, when you take into consideration how little is required to dissolve and remove sap from your car, and, given the speed at which alcohol evaporates, you would be hard pressed to actually harm your finish to any noticeable degree.
I have purposely done extensive, non-scientific testing on this subject to prove my hypothesis and have yet to create ANY damage whatsoever. Period. And, as expected, under close inspection of the areas where the sanitizer was used, the wax/sealant was removed - although the synthetic sealant fared much better than did the wax.
Bottom line, if you use it sparingly and keep the area treated minimized, you won't do any damage to your finish.
Now, having said that, the product I've found to be the absolute fastest that was specifically made and marketed for tar, sap, bugs, etc. is Bugs-B-Gone from the folks at SeaFoam. Why they chose such a corny, pedestrian name for a product that works so damn good is beyond me. you'd think that if they wanted people to take the product seriously, they would have named it something a little less...., oh I don't know... STUPID! :laugh
All joking aside, the stuff is amazing and does exactly what it says it will do.