a good Astro is a really excellent ride, so smooth and quiet. i'd personally rip the exhaust off and put a stock one back on - a luxuary vehicle should be silent unless its got sporting pedigree (AMG Merc, Audi RS, BMW M, Maserati Quattroporte etc)
lets face it, the only 'sport' you'd ever associate with an Astro is probably an eating contest.... long distance cruiser par excellence though.