I have a Astra G 1999 hatchback, edition 100, 1.8L/16V
My muffler is totally rotten and I will need a replacement. Now, I was thinking to change the stock muffler to an aftermarket one, but I do not quite know what would sound good and does not give any complications in flow.
I was think to either:
1. use a single muffler with a double exhaust pipe (single side of the car)
2. use a muffler on each side of the car

Would the second option create enough flow with my stock engine, so that I will not have an 'echoing' sound coming from the mufflers, end up with power loss and/or bad fuel economy?
Or would the first option be better.

Of course it would be possible to create a dummy side exhaust, which might look great, but is actually not that great, in my eyes.

Anyone any opinion/advice/experience?