In my experience most multimeters are good enough for basic vehicle diagnostic. All have accurate enough voltage measuring to tell if something is amiss with the battery, charging or cranking. Most have a few current ranges, though for vehicle use a relatively high current range up to several amps or 10A is handy.
For higher currents a clamp meter is useful as Karl points out. I have a cheaper Canadian tire version $20 or $30. The Elenco one Karl points to is likely better. Make sure you get a clamp that does both AC and DC. Some cheaper ones do only AC.

I have had at least 20 digital multimeters. I have four of a type similar to the Harbourfreight free coupon one. These four I bought personally in China in 1998 - 20 years ago. All 4 still works well. For those without the coupon the same multimeter can be bought for $3 from ebay, or same  / similar ones for $6 in stores.
If there is something I think is overrates it would be auto ranging. I prefer a fixed range. At least the cheaper auto-ranging ones I've had take a long time to figure out the range. Not good when one tries to measure the transient low battery voltage just as the started turns on.
I had one expensive Swiss BBC multimeter - $200 or $300 (BBC was the Swiss part of ABB before they merged). It lasted over ten years, but unfortunately also expensive multimeters are destroyed by user error.  I prefer when due to my mistakes $3 goes up in smoke not $300
Martin 

    On Saturday, April 21, 2018 12:37 AM, Karl Mullendore <tdiguru@WESTYVENTURES.COM> wrote:
 

 I find it invaluable to have a multitmeter with DC-amps function. I've been
using one of this model for years with good service and reasonable price:

https://www.amazon.com/gp/product/B001VGND88

Karl