Just having a think about the sponsor interest... not that you need it but has anyone ever got a 5* sponsor interest rating? I suspect it works much the same as developing parts and the closer you get to 5* (100%) the less progress is made in gaining their interest.
They do decrease if you dont give them some loving yes.
As for 5* it can be displayed differently in two places. On the sponsor list if you get over 4.5 out of 5 it displays as 5*, if you assign commercials to the sponsor it will show up as 4.5* in the negotiation window. A good way to know the exact true value is by hovering over the stars when you choose to embrace/negotiate with sponsors. I have one on 99.96% but by my calcs it will take 163 days to get to the full 100% (5*) rating.
I was keeping a spreadsheet of sponsor interest for a while, and was able to accurately predict how long gaining interest to a certain level would take.
At the time I was finding that as each hour passed, progress was around 0.04% less than the previous hour and that percentage was increasing by 0.000017% per hour.
I would guess this varies depending on how quickly you're progressing towards 5 stars?
Very odd but my sponsor just hit the 5* interest. It went from a 0.00001% increse per hour and requiring 163 days to reach max to suddenly being done. Perhaps my commercial took them out for a celebratory dinner or something lol!
Don't talk to me about sponsors!!! I created Blue Movies (among others) and set 60 commercials at 90% working with them. At 2* interest started negotiations. 3 weeks later at 5* interest realised the reason negotiation were not getting any ware because they don't want to sponsor a div 3 team!!! Bah.
I had even done a livery for next season with the sponsors on it ready.
Hahahahaha! Thats brilliant Dan! admittedly i had a similar issue but i realised early that the problem existed.
As for 60 commercials on one sponsor, i think thats too much mate, there is a limit where adding more comms doesnt really have an effect i think? I havent tested big numbers though so may be wrong?