Would you get custom parts or bolt on parts for your Elantra coupe?

With the endless amount of parts manufacturers and specialty shops that offer to make one-off parts which one do you prefer? Obviously bolt-on parts are cheaper since its mass produced. But theres also a downside that the parts might not fit perfectly or might need modification. But if you get something custom made you know it fits perfectly and works right away. But it will definitely cost a lot more. Discuss!!!