Side exit can be added to an Aero by the factory for around 1000 or so. You could go for the supersoorts double pipe exhaust if you go this route which sounds fantastic...
Miles are a good thing - means less issues to sort out, low mileage cars haven't always had all the little niggles a handmade car can have sorted out. My most solid Aero was my S4 and it came to me with 20k on the clock..
No I won't put the roof down.