Got an oval tip on my cat-back system last year, but I have to admit it was mainly because all the other options were ridiculously large chavvy drainpipe diameters.
Depends on whether you want your car mistaken for a
Cupra R or not??
But depending on its state of tune that might be making promises you can't keep?
If the car looks standard I reckon go for a 2.5" small single pipe for that Q-car look, or maybe a larger turned-down single pipe for diesel chic?