Hello, As most of you may have done, I've prepaid property taxes for Q1 and Q2 of 2018 in December 2017. Where do i enter that in turbo tax

You simply add these amounts to the other property taxes you may have paid for 2017 to come up with one total number.  But, if your 2017 property taxes were reported on Form 1098, then you should enter the 2017 amounts with your mortgage interest in the Form 1098 section and then use the other property tax payments section to enter the 2018 amounts. 

• Log into your account and click Take Me to My Return (you must click this first)
• Use the search function (magnifying glass in top right-hand corner) to search for "property taxes" and click the "jump to property taxes" link
• Follow the screens to enter your property taxes

Please make sure you keep documentation that your property taxes were assessed and paid in 2017.  In order to be deductible, your 2018 property taxes must have been actually assessed and paid in 2017.  

See IRS Advisory - Prepaid Real Property Taxes May Be Deductible in 2017 if Assessed and Paid in 2017