Firstly thank god I am not the only bloke out there with a Sirion 1.5 SX, and coincidentally mine is also silver and 2008. I was beginning to wonder if I had the rarest car in UK - in fact I still think that because I have never seen another one.

Regards your steering rack noises it does appear that Sirions do have a mystery knock sound from the steering bits. I owned a 1.3 abroad for 6 years and it knocked occasionally and randomly from new. The dealers checked it out thoroughly because I nagged them incessantly but all to no avail. I eventually accepted that it was just the way it was and it had absolutely no bearing on how the car behaved. It just seems to be a feature of the type, which is born out by several internet posts I have seen on the subject.

My current Sirion also does exactly the same and I am not in the least bit concerned. The steering is well balanced and operates just fine. My advice is to ignore it and relax because my personal experience is that the noise is not a symptom of impending failure - it just does it for some bizarre reason.

On the subject of 1.5 models, I always covetted the larger engine but never swapped until I returned to the UK. The 1.3 is an awesome engine and will fling the Sirion at a great rate of knots, but the 1.5 is a different matter. Personally I don't notice any huge difference of acceleration from a standstill (although there is a difference) but the torque of the larger engine is very noticeable around town and on the cruise. Changing down a gear to get up and go just isn't required when on the cruise, and moving about town in 4th is a wonderful thing.

I have driven a 1.5 Suzuki Swift and the engine is very low on torque but revs very quickly, whereas the Siron 1.5 has much more torque but isn't quite as free revving. The difference is that the Sirion engine is of a longer stroke type and hence the greater torque. I prefer the Sirion.

So there we have it.