Wheel adapters are generally not advised. There are certain applications that work out OK, but many adapters place unintended shear loads on the wheel studs/bolts and can result in vibration or loss of wheel under severe duty (pothole, high speeds, high lateral forces etc). The forces and additional shear surfaces also encourage the wheel to move around with respect to the hub/flange and this loosens the wheel bolts/nuts.
Wheel adapters are a necessary evil in certain odd applications. In your case, plenty of wheels are sold that are designed to fit your car. I'd stick to them.