Was thinking of getting a 'lower end' fault code reader for my RRS and the wife's Renault Scenic. Am I wasting my time? Only thinking of spending about £50 so not expecting the world, but some basic diagnostics would be nice.....I've no experience with these devices so any advice appreciated...

You'll only get basic engine management fault codes fo that generic type of tool. Bodsys Brake Bible
Software Updates Contact me
RRS Timed Heat/Remote kits - Contact me
BAS Engine Re-maps/ EGR Blank EuIII and EuIV
Clock On The Dash/ SNOTM /3Flash / BT Update /Service Reset/Error Codes read\ Gearbox Reset
See it HERE

Bodsy you actually might be wrong here
as i agree with You 100%

there always is a cheap solution:

http://www.obdchina.com/jlr-mongoose-for-j...-1620.html

The Chinese Mongoose knock-off alone will not do you much good - you still need IDS or SDD (OEM LR diagnostic SW) to make it work. And in my experience, using Chinese knock-offs and illegally copied SW is anything but plug n play - though it can be fun if you have time and patience

If you are not into playing with automotive electronics and computers, I'd suggest looking at the newer offerings in LR specific diagnostic tools: specifically that would be the Blackbox Nanocom or our IIDTool. Aside from legal/moral issues with Chinese copies /illegal SW, the big difference is that both of these products come with a guarantee and support. Generally, they end up costing less in the long run.

Both are avail for somewhat over GBP300 and can do much, much more than any other diagnostic system in this price class.

I am obviously biased, but here is a link to our new product / update announcement thread
http://www.rrsport.co.uk/forum/topic33984.html 
gap-diagnostic.com

I bought an Autel Maxiscan MS509 for about £28. Yes it only covers engine management faults, but it has saved my nephew money twice when I read the faults & re-set his management light. The MS509 can log faults and can be downloaded to a PC or laptop.

It's a good addition to any toolbox at the price. They're cheap now that Autel has a newer model out.

I got mine from here:

http://www.amazon.co.uk/Maxiscan-MS509-Autel/dp/B001LHXTO0 I'm in the shed, I'll be back in the real world in a minute.