Don't worry, I don't think anyone thought that a service was a mod, it was more of a lookout whilst on the subject - I just made a point of it being a mod as 'shane' was rude and just unnecessary and I took exception so bounced it back - I know, me bad...
...that said, isn't better oil an 'upgrade'
I took a nice route with modding on mine but more by opportunity than deliberately setting out to do it in any order. Clutch failed on mine so that was first. Then a used Stillen intake came up on ebay which I won for £57 (bargain!), then a member on here sold me his milltek exhaust (thanks Doogyrev!), then I got a set of Volks wheels off another member on here which were going relatively cheap.
Followed that with properly priced stuff of spacer, HFCs and uprev then worked on the body with stillen front lip and side steps.
Actually, two very minor mods which vastly improved my driving experience were a chunky handbrake handle and weighty gear knob