Ruthie
It depends upon the strength of your need to retain a vehicle of any value.
It is not uncommon for families with large numbers of children to require expensive people carriers, if you are working in a prestigious sales position then you are expected to look the part, or if you live in a very rural area you might need a larger than average 4 wheel drive.
There are no real benchmarks, just common sense and good IPs that justify your case for you!
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk