Anyone know of " an after market blindspot monitor system" for a 2012 IS 350C?

 

I have just bought one and all was going well until I had to tap into the reverse backup light wire. Now still looking for a way after 3 days as no onw seems to know what to do for the convertible as direct wiring to the reverse light would tangle and break due to the double hinge. Can anyone direct me to a reverse wire I can use?

I bought the 79hrz as shown called D5 https://www.aliexpress.com/item/1005...64cd1802Ny4Sth
Color Name:77G monochrome D5