you are not gaining anything by wiring the speakers together. you will only be using 1 channel of the amp to drive both, so you will have the same output as if both were connected on their own.
using your numbers and making it simple....
stock amp is 50w per channel at 2ohm
speakers wired down to 2ohm on a single channel of the amp = 50w / 2 speakers = 25w per speaker
speakers wired on their own channels at 4ohm on a 2ohm amp = 25w per speaker
all you are doing is losing the ability to fade left to right. you are not gaining a thing.
using your numbers and making it simple....
stock amp is 50w per channel at 2ohm
speakers wired down to 2ohm on a single channel of the amp = 50w / 2 speakers = 25w per speaker
speakers wired on their own channels at 4ohm on a 2ohm amp = 25w per speaker
all you are doing is losing the ability to fade left to right. you are not gaining a thing.