Reinsurance

Good Day, I am studying reinsurance and have come across a question which I am struggling to obtain an answer to. I would appreciate it if you could take a few minutes of your time for assistance with this tremendously.
You are a reinsurer. You are asked to provide a quota share treaty to a motor insurer. The portfolio of business shows a small underwriting profit. The profile shows that the bulk of risks have sums insured below R500,000, but there are some vehicles valued up at to R1,000,000. These vehicles have consistently evidenced a much lower loss rate and cost of claims than the main portfolio.

1.1 You decide not to offer the requested cover. Give reasons why reinsurers are loath to offer Quota Share Treaties in this class
1.2 Assume a net retention of R250,000 on any one vehicle/R500,000 on any one loss.
What are the non-proportional/proportional treaties (with applicable limits) that would be suitable to enable the insurer to retain the portfolio but limit the exposure to his net retention in respect of:
1. Any one vehicle
2. A loss involving multiple vehicles possibly in multiple locations
3. The total cost of losses in any one year
Thank you very much for your time.