Nice one! Any chance you could post a link to where the instructions are for the OBD reader please? I'm guessing they're on here somewhere but not sure where to start looking!
On another note, i've just re-read the thread and it seems i missed your post about not being able to get hold of a 1k8 (1.8k) resistor. You're right, it is a preferred value and i had no trouble finding it listed by the supplier i use -
Spiratronics 1k8 resistor - they do other variants of that value as well (higher/lower power, construction etc) and they also do a wide range of
toggle switches too. I've been using them for 2-3 years now and generally speaking they are cheaper than most other places (much cheaper than Maplins most of the time!), have very good customer service and sensible delivery charges. For example i bought a mixture of bits a month or two back (resistors, LEDs, capacitors, heat shrink sleeving, USB sockets etc) that came to about £15 for the components and the P&P was just £1.49.
If you tinker with electronics as a hobby (as i do, it was my career once until redundancy) then Spiratronics are well worth adding to your bookmarks. Granted they can't get everything but i've seen their range grow in the time i've known them so maybe one day they will have everything you could possibly imagine!