At some point you are going to pick up an ignition related problem of sorts, be it HT leads (The wires that go to the spark plugs) injectors (Very rarely go) and so on.
UPDATE:
So I've been tinkering with coils recently, my local electronic ECU repair station reckons Hyundai coils are the same, I managed to get 4 for testing purposes on a customers car.....mmmm bad move and they blew at around 500 km's of use so don't go the Hyundai route.
Without going into details of wasted spark technology I'll let the pictures do the talking!
We have brand new coil packs in stock.
Loose single coils R900
Complete coil packs R2870
Coils can easily be replaced once coil pack has been removed
Later models use the square Bosch coil pack and there are two of them.