The Hyundai forum is about as lively as a morgue so thought I'd ask here.
Bit of a strange one, not sure if its electrical issue or not. Sometimes the car feels likes its misfiring, kinda like its stuttering (if a car could do that) when accelerating usually under 40 mph mainly 2/3/4th gear but has been small issues in 5th at a little over 40 mph. It doesn't happen all the time and can happen when the engine is warm or cold.
Just changed the spark plugs from NGK R BKR5E (were on the car when I got it) to some Bosch Super 4 as recommended by euro car parts, idles better but on first test drive it actually performed worse. Felt better coming back via the A1 and opening it up a bit.
It appears to have had some kind of service before I bought it as the air filter is clean and new looking the ignition leads look good and new, spark plugs did look iffy hence the change and there was verrry little oil in it, only other thing I can think of is fuel filter but I cant find it, guessing its under the car and its a low sitting car so hard to see under.