Can I get my child a car with money from his trust ?

You need to have the trust explained to you.  Contact the trustee to see what the requirements for distributions are for your child's trust.  Most trusts have a HEMS standard for distributions.  This means the trustee can provide money for the health, education, maintenance and support of the beneficiary.  A car woudl typically be something a trtustee could do under these standards, but the decision is in the discretion of the trustee. A trustee can be called to task if he is too tight with the distributions.