Yes, much like F30, I can't make it balance absolutely, but agree that the reducing balance approach is right.
The numbers are something like:
45625.50 224.33 221.01 217.67 214.32 210.96 207.57 204.17
899.06 899.06 899.06 899.06 899.06 899.06 899.06
44950.77 44272.71 43591.33 42906.59 42218.49 41527.00 40832.12
200.76 197.32 193.87 190.41 186.92 183.42 179.90 176.37
899.06 899.06 899.06 899.06 899.06 899.06 899.06 899.06
40133.82 39432.08 38726.89 38018.24 37306.10 36590.47 35871.31 35148.62
172.81 169.24 165.66 162.05 158.43 154.78 151.12 147.45
899.06 899.06 899.06 899.06 899.06 899.06 899.06 899.06
34422.37 33692.55 32959.15 32222.14 31481.50 30737.23 29989.29 29237.68
143.75 140.04 136.31 132.56 128.79 125.00 121.19 117.37
899.06 899.06 899.06 899.06 899.06 899.06 899.06 899.06
28482.37 27723.35 26960.60 26194.09 25423.82 24649.76 23871.90 23090.21
113.53 109.66 105.78 101.88 97.96
899.06 899.06 899.06 899.06 19559.45
22304.67 21515.28 20722.00 19924.82 463.34
Each of these 36 columns represents the situation at the end of each successive month of the 36 month contract. It reads left to right, then down to the next block of numbers.
The top number in each block is the interest due during that month (it reduces as the balance gets paid off), the second number is the payment you made (£899.06 each month except the last month) and the third number is the outstanding balance at the end of the month.
It isn't far out, so something in my assumptions is not quite right.
(I used MS Excel to do this quickly)