Question:
1. Can someone suggest a good Car rental for car + driver (English speaker) in Iran.
2. Business visa Application: does the invitation letter has to be validated by Iran Foreign Affairs before sending to the visitor? do we need to show hotel booking?
3. Tourist Visa Application: do we need an invitation from someone in Iran? invitation needed to be validated by Iran Foreign Affaiers? is Hotel booking required? what's the process of application?

Answer:
1. For the transfers and transports in Iran, you can check: http://www.iranairporttransfer.com
2. The businessmen who are traveling in Iran for the business purposes should apply for a business visa through the company they want to meet.
3. But Iran tourist visa issuance is easily done in the below three ways:
A. Fill in the visa form on http://www.uppersia.com/Iran-travel-services/iran-visa.html, it takes about 10 working days to get your reference number and two working days to collect your visa at the embassy by direct referral or one working week by posting the docs to the embassy. You can pay the visa fee in cash in Iran.
B. Fly to Iran and get a 15-day on arrival visa at the airport. This kind of visa is issued for 98 nationalities excluding USA, England, Canada, Colombia, Pakistan, Afghanistan, Iraq, Jordan, Bangladesh, and Somalia. If your nationality is among the countries authorized to get it, you can collect your visa against offering your passport, a passport-size photo and about $50 to the staff at the airport. There is no need to fill in any form beforehand.
C. Refer to the Iranian embassy in your country and ask for a visa to be issued for you. Usually this way takes longer time about 30 daysso it is not suggested. By the way, some of the embassies ask for an invitation letter, in this case you have to use the first option.

Check cheap Iran tours at http://www.uppersia.com/Iran-tours