Changing my tires on the stock rims. I got 245/35/18 because I want to reduce the sidewall. I purposely choose the aspect ratio, but the tire shop and concerned parents keep telling me I should stick with 245/45/18. Need some opinions because I don't think what I'm doing should raise eyebrows so high.

 

it will look really weird in my opinion if you are staying with stock wheels

 

I believe your ride will be a little harsher with the stiffer sidewalls with that aspect ratio. It will look funny as well. Do check if there will be any tire rub of the components as well.

I would stick with the OEM size.

 

Beware that with the smaller sidewall your speedo error will get worse.
My LS430 speedo currently reads 78Mph when the SatNav is showing 70Mph on 245/45-18 tyres, but with the 245/35-18 tyre size yours will be showing 84Mph.

 

Is your car slammed or stock height?