Pls help - perquisites query

Hi, Pls help me with the following queries:

 1. Can we claim HRA exemption also if we get accommodation from employer ( not owned by employer but taken on lease from third party) which is valued under perquisites in sub-rule(1) but some part of rent is paid by employee to owner of accommodation?

2. Telephone provided by an employer to an employee at his residence is exempt perquisite only if the employer is a telecom company or exempt for all employees?

3. Kindly explain motor car rent exemption allowance proviion

4. what components of salary should be taken into consideration for valuing perquisite for accommodation?

Thanks,