Answer before the question is asked
Most people who abandon a rental enquiry do so because they cannot find the daily rate, the deposit amount or the age requirement. Put those three facts on the page where the decision happens and the number of half-finished enquiries falls immediately.
We moved the price onto every car card, next to the seat count and gearbox. Enquiries became shorter and better qualified the same week.
Make the first reply the useful one
A response that only says "thanks, we'll get back to you" creates work for both sides. Send the availability, the total for the dates requested and a link to confirm. If the car is not free, offer the closest alternative in the same message.
Reduce the booking to one decision
Long forms lose people. Name, email, phone, dates and the car — that is the whole form. Everything else, including the license number, can be collected at the counter when documents are physically checked anyway.
Measure the handover, not the click
Clicks and page views flatter a report but do not pay for fuel. Track enquiry-to-booking rate and booking-to-pickup rate. A campaign that produces fewer enquiries but more pickups is the better campaign.
Follow up once, then stop
One reminder 24 hours after an unanswered quote recovers a meaningful share of lost bookings. A second and third reminder mostly annoys people who have already rented elsewhere.
Keep the fleet visible
Repeat visitors are the cheapest leads you will ever get. Showing the full fleet, the categories and a clear phone number on every page means a returning customer does not have to start from the homepage again.