Letter for corporate sponsorship

I was going to write to my customer (Hewlett Packard) and my employment agency to suggest they buy some space for decals on the car for the Rally.

I'm only so good with word and I was wondering if one of the more experienced of you might have a template I could steal/bastardise.

I've spoken with one of the senior managers who says he wants it emailed completely cold so he can forward it to bean counters with his recommendation to support the cause. I think he means he wants it professional with no familiarity rather than me saying "Hi Pete, as discussed"

Any guidance on how much I should ask for would be appreciated too

Thanks again...