Section 314. Security interest in other property

No retail instalment
  contract, or any other agreement executed in connection therewith, shall
  provide for the creation of a security interest in any personal or  real
  property,  other  than  the motor vehicle which is the subject matter of
  the retail instalment  sale  (or  accessories  therefor  or  special  or
  auxiliary equipment used in connection therewith), to secure the payment
  of  the  time  sale  price  under  such  contract  or  any part thereof,
  provided, however, that the prohibition of this  section  shall  not  be
  applicable  to  the taking of a mortgage or other security interest upon
  or in connection with real property to secure the payment  of  the  time
  sale  price  of  a retail installment sale, if the subject matter of the
  retail installment sale is a mobile home  or  trailer  which  is  to  be
  annexed  to  or  situated  on  such  real  property. Any such prohibited
  provision shall be void but shall not otherwise affect the  validity  of
  such contract.