I've had one car with an airbag warning light (pre-tensioner replaced) and another with a traction control light (Thales ABS) fail the MoT this year after passing a few times. The garage made both of them disappear without making an explicit charge nor obviously disturbing the dashboards.
Neither was a Fiat, so that is not a lot of help unless you are in Lancashire.
If the difference in price you would receive when selling is more than the cost of repair, it is obviously worth fixing. Also consider what you would replace it with and likely costs and benefits over 2 years. If you are still happy with a 1.2 Stilo that you have owned from new, it is likely to be worth spending over £300 to keep it going.