nothing beats a scalpel for fine cutting i got mine from a jewellery supply store try hobby shops if they dont have i know chemists keep the blades not sure if they keep handles also:dunno:
I used a stanley knife to trim the lamin-x for my tail lights. Bought a pack of 3 for R20 from the local midas. They are adjustable and sharp.
When lamin-x'ing the tails, leave a little on the edges, heat the edges then use a card (credit card :clap to push the tint in between the tail light and body of the car. Looks neater and complete.