Hello David,
Go for an uncomplicated model. For basic car fault-finding all you will need is:
- A 20v DC range
- A low resistance range, for example 200Ω or below.
You're less likely to need DC current but even meters costing as little as £6.99 come with a 10 amp range. Eliminate any which cannot read above 200mA.
If you'd like to expand upon the electrical problems you wish to tackle, I might be able to advise further.
Simon