is this even possible? is there a 12v contact that can supply 300+ amps on the model s? i haven't had to boost alot of cars but when i need it, its REALLY NEEDED! (kind of like insurance)
The only kind of jumpstart that you would need for a Model S would be if the 12V battery is dead. There are jumper terminals behind the upper right nosecone. You remove the nosecone with a credit card or similar tool. To jumpstart another car, the best way is to carry one of those jumpstart kits that includes a battery. The 12V battery in a Model S is like a small motorcycle battery--tiny.
As Jerry mentioned, there are two posts behind the nosecone. They will not supply 300 amps. As he mentioned, there is only a small motorcycle battery, and the DC-DC converter is limited in terms of supply potential. In theory, you could use model S to charge an ICE battery (probably at 40 amps or so) by having someone sit in the driver's seat and Model S turned "on" with those posts connected to the ICE. 15-20 minutes might give enough for a crank or two. However, you should not try starting the ICE with Model S connected. Also, some of the voltages we have seen on the model S are considerably higher than those found in traditional ICE's (15+ volts in some cases). Some components in the ICE may not be able to handle that. ...and I imagine that Tesla considers this a no-no.
Good points FlasherZ. Do not be surprised if a 3rd party vendor designs a device that enables safe charging for an EV to ICE battery or from EV to EV.
I was told explicitly by Tesla to not use to jump start another car. Wife's car was dead and bought a battery charger / compressor to get it started.
The thing is that if the other car tries to start while connected, it's almost certain to fry something [expensive]. It just barely possible to do this with the Prius if you take the keys from the other driver so that they don't try to start their car until the cables are removed--but it's not recommended. The small 12V Prius battery looks big compared to the Model S battery, so it's totally a no go with the Model S.