There's the saying that cash is king. Especially in cases where one like yourself can afford it. Rough calculation, if you paid some and took an 80K loan for say 5 - 9 years? Just cuz "loan"...Interest could be around 10K++. So IMHO, if you could use that 80K to make around 20K or more in the same amount of years?.. Then sure, go the loan route as it's smart. But this won't apply to everyone. Some people prefer to pay cash and or settle their loans quickly. Ultimately, it really depends on your financial situation and how you feel about loans.

Regarding discounts.. I don't think it'll be much la. Cuz end of the day, SA knows you want the car, you also know you want the car ... and so discounts can only be so much. Definitely not extra until more that say interest above if you use loan vs cash. Just milk as much as you can and enjoy your ride. My 2 sen.
Ah, I didn't know about this.. I always thought it's just part of the job description to close the sale...Sure more hassle to handle loan docs, apply to different banks, etc vs a clean single deposit and the car's completely yours...But i guess being paid for all that extra work (from the SA POV), is justified.